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Cover: Photographs of Lake Roosevelt, Washington, clockwise from upper left: (1) Exposed lakebed sediment near the Marcus 

Island Campground (lake elevation 1,222 feet, March 13, 2001). Windblown dust is visible near the opposite shoreline. Photograph 

taken by Sue C. Kahle, U.S. Geological Survey. (2) Exposed sediments near Kettle Falls (lake elevation 1,217 feet, April 24, 2001). 

Photograph taken by Michael S. Majewski, U.S. Geological Survey. (3) Seven Bays and Lake Roosevelt (lake elevation 1,222 feet, 

March 13, 2001). Photograph taken by Sue C. Kahle, U.S. Geological Survey. (4) Wind-blown dust along the shore at the confluence 

of the Spokane River and Lake Roosevelt (lake elevation 1,222 feet, March 13, 2001). Photograph taken by Sue C. Kahle, U.S. 

Geological Survey. 
Concentrations and Distribution of Slag-Related 

Trace Elements and Mercury in Fine-Grained 

Beach and Bed Sediments of Lake Roosevelt, 

Washington, April–May 2001

By Michael S. Majewski, Sue C. Kahle, James C. Ebbert, and Edward G. Josberger

Tacoma, Washington

2003

Water-Resources Investigations Report 03-4170

U.S. GEOLOGICAL SURVEY

Prepared in cooperation with the

CONFEDERATED TRIBES OF THE COLVILLE RESERVATION, 

LAKE ROOSEVELT WATER-QUALITY COUNCIL,

BUREAU OF RECLAMATION, and

NATIONAL PARK SERVICE
U.S. DEPARTMENT OF THE INTERIOR

GALE A. NORTON, Secretary

U.S. GEOLOGICAL SURVEY

Charles G. Groat, Director

Any use of trade, product, or firm names in this publication is for descriptive purposes only and does 

not imply endorsement by the U.S. Government.

For additional information write to:

Director, Washington Water Science Center

U.S. Geological Survey

1201 Pacific Avenue – Suite 600

Tacoma, Washington 98402

http://wa.water.usgs.gov

Copies of this report can be purchased from:

U.S. Geological Survey

Information Services

Building 810

Box 25286, Federal Center

Denver, CO 80225-0286

Suggested citation:

Majewski, M.S., Kahle, S.C., Ebbert, J.C., and Josberger, E.G., 2003, Concentrations and distribution of slag-related 

trace elements and mercury in fine-grained beach and bed sediments of Lake Roosevelt, Washington, April–May 

2001: U.S. Geological Survey Water-Resources Investigations Report 03-4170, 29 p. 
Contents iii

CONTENTS

Abstract ................................................................................................................................................................ 1

Introduction .......................................................................................................................................................... 2

Purpose and Scope ...................................................................................................................................... 3

Description of Study Area........................................................................................................................... 3

Acknowledgments....................................................................................................................................... 5

Data Collection and Analysis............................................................................................................................... 5

Sampling Design ......................................................................................................................................... 5

Sampling Methods ...................................................................................................................................... 7

Laboratory Analysis.................................................................................................................................... 10

Quality Assurance ....................................................................................................................................... 10

Concentrations and Distribution of Slag-Related Trace Elements and Mercury................................................. 12

Reference Sites............................................................................................................................................ 12

Riverine-Slag Site ....................................................................................................................................... 12

Targeted Areas ............................................................................................................................................ 12

Spatially Distributed Areas ......................................................................................................................... 18

Other Trace Elements.................................................................................................................................. 21

Comparison of Concentrations of Slag-Related Trace Elements with Sediment-Quality Guidelines........ 24

Implications to Airborne Trace Metal Concentrations................................................................................ 25

Summary .............................................................................................................................................................. 25

References Cited .................................................................................................................................................. 27

Appendix 1. Analytical results and relative standard deviations for duplicate samples and National Institute 

of Standards Technology reference material for quality control..................................................... 28
iv Figures

FIGURES 

Figure 1. Map showing location of the study area and sediment collection sites on Lake Roosevelt 

and the upper Columbia River, Washington and British Columbia, April-May 2001 ...................... 4

Figure 2. Satellite image showing example of sampling transect and spacing of sampling sites at 

SD12 across an exposed area of sediment on a section of Lake Roosevelt, Washington ................. 8

Figure 3. Hydrograph showing water-surface elevation of Lake Roosevelt at Grand 

Coulee Dam during 2001 drawdown ................................................................................................. 9

Figure 4. Graphs showing gradients in concentrations of slag-related trace elements 

and mercury in fine-grained sediments along Lake Roosevelt and the upper 

Columbia River, Washington and British Columbia, April-May 2001............................................. 15

Figure 5. Graph showing gradients in concentrations of aluminum, iron, and titanium in 

fine-grained sediments along Lake Roosevelt and the upper Columbia River, 

Washington and British Columbia, April-May 2001......................................................................... 21

Figure 6. Plot of natural logarithm of the aluminum-normalized concentrations of zinc, copper, 

and arsenic in fine-grained sediments with respect to river mile along Lake Roosevelt 

and the upper Columbia River, Washington and British Columbia, April-May 2001 ...................... 23

Figure 7. Graph showing gradient in concentration of tin in fine-grained sediments along 

Lake Roosevelt and the upper Columbia River, Washington and British Columbia, 

April-May 2001 ................................................................................................................................. 23

Figure 8. Plot of natural logarithm of the tin-normalized concentrations of lead, arsenic, and 

cadmium in fine-grained sediments with respect to river mile along Lake Roosevelt 

and the upper Columbia River, Washington and British Columbia, April-May 2001 ...................... 24
Tables v

TABLES

Table 1. Location and description of sediment-sampling sites on Lake Roosevelt and the 

upper Columbia River, Washington and British Columbia, April-May 2001................................... 6

Table 2. Trace elements and other constituents analyzed for in fine-grained beach- and 

bed-sediment samples from Lake Roosevelt and the upper Columbia River, 

Washington and British Columbia, April-May 2001......................................................................... 11

Table 3. Concentrations of trace elements and other constituents analyzed for in 

sediment samples collected from Lake Roosevelt and the upper Columbia River, 

Washington and British Columbia, April-May 2001......................................................................... 13

Table 4. Comparison of slag-related trace elements and mercury concentrations in samples from

riverine slag deposit collected April-May 2001 with concentrations from studies in 1995 

and 1999 and from treated slag sampled in 1992, Lake Roosevelt and the upper Columbia 

River, Washington and British Columbia.......................................................................................... 18

Table 5. Comparison of median concentrations of slag-related trace elements and mercury with 

median concentrations from a 1992 study and with riverine slag, treated slag, and 

Canadian sediment-quality guidelines ............................................................................................... 19

Table 6. Concentrations of slag-related trace elements and mercury measured at two

locations on Hall Creek, a minor tributary entering Lake Roosevelt, and at sampling area 

SD10 on Lake Roosevelt, Washington .............................................................................................. 20
vi Conversion Factors and Datums 

CONVERSION FACTORS AND DATUMS

CONVERSION FACTORS

Concentrations of chemical constituents in water are given either in milligrams per liter (mg/L) or 

micrograms per liter (μg/L) or in parts per million (ppm).

DATUMS

Sea level: In this report, "sea level" refers to the National Geodetic Vertical Datum of 1929 (NGVD of 

1929) — a geodetic datum derived from a general adjustment of the first-order level nets of both the 

United States and Canada, formerly called Sea Level Datum of 1929.

Vertical coordinate information is referenced to the National Geodetic Vertical Datum of 1929 

(NGVD 29).

Horizontal coordinate information is referenced to the North American Datum of 1983 (NAD83).

Multiply By To obtain

Length

inch (in.) 2.54 centimeter

inch (in.) 25.4 millimeter

foot (ft) 0.3048 meter

mile (mi) 1.609 kilometer

Area

acre 4,047 square meter

acre 0.004047 square kilometer

Mass

ton per day (ton/d) 0.9072 metric ton per day
Abstract 1

Concentrations and Distribution of Slag-Related 

Trace Elements and Mercury in Fine-Grained Beach and 

Bed Sediments of Lake Roosevelt, Washington, 

April-May 2001

By Michael S. Majewski, Sue C. Kahle, James C. Ebbert, and Edward G. Josberger

ABSTRACT

A series of studies have documented 

elevated concentrations of trace elements such as 

arsenic, cadmium, copper, lead, mercury, and zinc 

in the water, bed sediment, or fish of Lake 

Roosevelt and the upstream reach of the Columbia 

River. Elevated concentrations of some trace 

elements in this region are largely attributable to 

the transport of slag and metallurgical waste 

discharged into the Columbia River from a smelter 

in Canada. Although most recent studies have 

focused on contamination levels in water, bed 

sediment, and fish, there is growing concern in the 

region over the potential threat of airborne 

contaminants to human health. In response to 

these concerns, the U.S. Geological Survey 

conducted an assessment of trace-element 

concentrations in the relatively shallow 

fine-grained sediment along the shore of Lake 

Roosevelt that is exposed annually during periods 

of reservoir drawdown. During each winter and 

spring, the water level of Lake Roosevelt is 

lowered as much as about 80 feet to provide space 

to capture high river flows from spring runoff, 

exposing vast expanses of lake-bottom sediment 

for a period of several months. Upon drying, these 

exposed areas provide an extremely large source 

for wind-blown dust.

This study concluded that trace elements 

associated with slag and metallurgical waste are 

present in the fine-grained fraction (less than 

63 micrometers) of bed sediments along the length 

of Lake Roosevelt, and as such, could be 

components of the airborne dust resulting from 

exposure, drying, and wind mobilization of the 

sediments exposed during the annual drawdowns 

of the reservoir. Trace-element concentrations in 

the surficial bed sediment varied, but the major 

components in slag—arsenic, cadmium, copper, 

lead, and zinc—showed generally pronounced 

gradients of decreasing concentrations from near 

the International Border to the Grand Coulee Dam. 

The results of this study provide base-line 

information needed to plan and conduct air 

monitoring of trace elements in wind-blown dust 

along Lake Roosevelt. 
2 Concentrations of Slag-Related Trace Elements and Mercury in Beach and Bed Sediments of Lake Roosevelt, Washington

INTRODUCTION

Contamination of Lake Roosevelt (formally 

named Franklin D. Roosevelt Lake) was discovered in 

the early 1980s, when elevated concentrations of the 

trace elements arsenic, cadmium, lead, and zinc were 

reported in fish collected near Grand Coulee Dam 

(Lowe and others, 1985). The occurrence of these trace 

elements is attributed primarily to the transport of slag 

and metallurgical waste from a lead-zinc smelter in 

Trail, British Columbia, Canada (Bortleson and others, 

2001). This smelter discharged slag directly into the 

Columbia River at a rate of about 397 tons per day 

from 1930 until the early 1990s (Cominco, Ltd., 1991). 

The smelter also discharged dissolved trace elements 

directly into the water from its wastewater system. 

In addition, particulate matter was discharged into the 

atmosphere from the furnace smokestacks until 1997, 

when a new smelter with improved air emission and 

effluent treatment controls began operation. Other 

sources of trace elements in Lake Roosevelt include 

runoff from active and abandoned mining operations in 

the region, and the Spokane and Pend'Oreille Rivers, 

which transport trace elements from mining areas 

around the Coeur d'Alene drainage basin (Yake, 1979).

In 1992, the U.S. Geological Survey (USGS), in 

cooperation with the U.S. Environmental Protection 

Agency (USEPA) and the Lake Roosevelt WaterQuality Council, initiated a large-scale study of 

sediment quality in Lake Roosevelt (Bortleson and 

others, 2001). The USGS reported that Lake Roosevelt 

beach and bed sediments contained elevated 

concentrations of the trace elements—arsenic, 

cadmium, copper, lead, mercury, and zinc—relative to 

background reference sites. Concentrations of these six 

trace elements were highest at the sites closest to the 

smelter source and decreased downstream. Laboratory 

tests showed that the sediments were toxic to benthic 

invertebrates, and that these communities in the Lake 

Roosevelt system were stressed, most likely from the 

elevated trace-element concentrations and from the loss 

of physical habitats due to the extensive slag deposits. 

In mid-1995, the lead-zinc smelter ceased 

discharging slag into the Columbia River under normal 

operating conditions. By 1999, effluent discharge was 

further reduced with the construction of a new smelter 

and improved effluent treatment controls (G3 

Consulting, Ltd., 2001). Although these actions 

resulted in a significant decrease in the current (2001) 

loadings of trace elements and slag to the system, large 

quantities of contaminated sediments remain in Lake 

Roosevelt. 

Previous studies conducted in Lake Roosevelt 

focused on contamination levels in fish, water, and bed 

sediment. There is, however, growing concern over the 

potential threat of airborne contaminants to human 

health. From about January through April every year, 

the water level in Lake Roosevelt declines substantially 

for flood-control purposes and extensive reaches of 

contaminated sediments are exposed. When the 

exposed sediments dry, the fine-grained material can 

become airborne and be transported throughout the 

Lake Roosevelt area by the prevailing winds. The water 

level also is drawn down for about 1 month in late 

summer. Bed sediments are exposed during this period 

as well, but to a lesser extent than during the primary 

winter-spring drawdown. 

Trace metals associated with the fine-grained 

particle fraction, designated as PM10 and having a 

mean diameter of less than or equal to 10 μm 

(micrometers), have a high potential for being 

entrained into the lower atmosphere by wind gusts. 

Once airborne, the particles are transported varying 

distances downwind, depending on their size and the 

magnitude and duration of the prevailing winds.

The population residing in the Lake Roosevelt 

area is concerned that they and the many visitors to the 

lake may be exposed to elevated concentrations of trace 

elements and total particulate matter during periods of 

high winds. Inhaled PM10 particles travel deeper into 

the lungs and are retained for longer periods of time. 

This is why PM10 is a primary health concern. The 

conclusions and recommendations section of the 

USEPA Preliminary Assessment Report (U.S. 

Environmental Protection Agency, 2000) expresses the 

extent of this concern with the following statement: 

"Additional concerns include potential exposure to the 

contaminated sediments during lake draw-down 

periods, such as the potential for health effects 

resulting from dermal contact with the sediment, or 

from inhalation of airborne sediment particles." 
Introduction 3

To address these concerns, the USGS, in 

cooperation with the Confederated Tribes of the 

Colville Reservation, Lake Roosevelt Water-Quality 

Council, the Bureau of Reclamation, and the National 

Park Service, conducted a survey of beach and bed 

sediments in April and May 2001 to determine the 

concentrations and distribution of trace elements in the 

fine-grained fraction of exposed beach, bed, and bank 

sediments along the Columbia River from the Canadian 

border to the Grand Coulee Dam. For this study, the 

fine-grained sediments were defined as those less than 

63 μm. These results are the first of a two-part study to 

assess the contributions from trace elements in exposed 

bed sediments to elemental concentrations of airborne 

particles measured during ambient and high-wind 

conditions. 

The primary focus of the study was the trace 

elements of environmental significance found in slag 

discharge. Copper, lead, and zinc are the major trace 

elements in slag, and arsenic and cadmium are the 

minor elements (G3 Consulting, Ltd., 2001). Mercury, 

although not a direct component of slag, also was a 

focus of the study. Mercury has entered the Columbia 

River at Trail as a component of slurry effluent from 

the smelting facility that was, until recently, also 

directly discharged into the Columbia River (Bortleson 

and others, 2001; G3 Consulting, Ltd., 2001). Other 

trace elements that were detected in the bed-sediment 

samples may have originated from the various mining 

operations in the watershed, as well as from 

mineralization, erosion, and slumping of bank deposits 

along the shoreline of the reservoir, especially in the 

middle and lower reaches (Jones and others, 1961).

Purpose and Scope

The purpose of this report is to present the results 

of the assessment of concentrations and distribution of 

slag-related trace elements in the beach and bed 

sediments along Lake Roosevelt. Samples were 

collected during the winter and spring drawdown of the 

lake, and concentrations were compared with 

concentrations at reference sites above lake level and 

upstream of contamination sources, with 

concentrations in a riverine slag deposit, and with 

concentrations measured in previous studies. 

Concentrations also were compared with Canadian 

sediment-quality guidelines. 

Description of Study Area

Lake Roosevelt, a reservoir formed on the 

Columbia River by the Grand Coulee Dam, is located 

in north-central Washington and extends about 135 mi 

upstream from the dam, reaching within about 15 mi of 

the International Boundary with Canada (fig. 1). The 

original purpose of the Grand Coulee Dam, completed 

in the early 1940s, was to provide irrigation water and 

flood control and to produce hydroelectric power. The 

reservoir, however, has developed into a major 

recreational and economic resource for the surrounding 

area. From 1992 to 2000, boating, fishing, camping, 

and general sightseeing attracted an average of 1.4 

million visitors each year to the Lake Roosevelt 

National Recreation Area (Roberta Miller, National 

Park Service, written commun., November 2001). In 

addition to the high-use camping and boating areas 

along Lake Roosevelt, there are several towns and 

many private residences close to the reservoir. Yearround residents who live near the reservoir and use it 

extensively include members of the Confederated 

Tribes of the Colville Reservation and the Spokane 

Tribe of Indians. Reservation lands currently border 

more than one-half the length of Lake Roosevelt 

(fig. 1). 

Each winter, beginning in January, the water 

level of Lake Roosevelt is lowered to provide space to 

capture high river flows, primarily from the Columbia 

River, that typically occur in May, June, and July from 

snowmelt in the drainage basin. The level of the lake 

can be lowered from the full pool level of 1,290 ft 

elevation above sea level (as referenced to NGVD 29) 

to 1,208 ft by the end of April or May, depending upon 

the amount of water predicted to flow through the 

system during the flood season. Typically, the reservoir 

is refilled (elevation 1,280 ft or higher) by July 1. 

During the flood-control drawdown period, power 

production, fishery issues, and irrigation also can affect 

daily water levels (Craig Sprankle, U.S. Bureau of 

Reclamation, Grand Coulee Power Office, written 

commun., November 2001). Since 1995, the lake level 

also has been lowered in August to increase 

downstream flow for salmon mitigation, but to a lesser 

extent than the winter drawdown.
4 Concentrations of Slag-Related Trace Elements and Mercury in Beach and Bed Sediments of Lake Roosevelt, Washington

SR

155

SR

174

SR

174

SR

155

SR

21

21

SR

20

SR

20

SR

25

SR

25

25

US

395

US

395

US

395

SR

231

US

2

231

SR

20

US

97

SR

20

SR

31

SR

172

SR

17

SR

291

2

292

Rufus

Woods Lake

River

Creek

Sanpoil

Creek

Hall

Lake

River

River

River

Colville

Long

Spokane

Spokane

Spokane

Hawk 

Creek

River

COL

Creek

Sherman

Kettle

Onion Creek

COLUMBIA

RIVER

Tulip Creek Rialto

Creek

Lower Arrow Lake

RIVER

Creek

Creek

Sheep

Sheep

Big

Little

Hanna Creek

River

Slocan

River

River

Pend

Oreille

FRANKL IN D.

ROOSEVELT LAK E

FRA

NKLIN

D.

ROOSEVELT

LAKE

Banks

Lake

Kooteney

Ninemi le

River

Little

COL

BIA UM

RIVER

UMBIA

CANADA

USA

Marcus Island

French

Rocks

Seven

Bays

Haag Cove

Base from U.S. Geological Survey

Washington State base map, 1:500,000, 1982

Canadian portion is based on information from the National Topographic System

map sheet number NTS 82-5 Nelson, edition 3 copyright 1986. Her Majesty the Queen in Right of Canada with permission

of Energy, Mines and Resources Canada, 1:250,000

10

0

0

10

20 30

20 30 40 MILES

40 KILOMETERS

118 ̊ 117 ̊ 30'

49 ̊ 30'

119 ̊ 30' 119 ̊ 30'

30'

49 ̊

48 ̊

WASHINGTON

UNITED STATES 

CANADA

Figure

location

Castlegar

Northport

Trail

Kettle Falls

Colville

Hunters

Inchelium

Fort 

Spokane

HUGH

KEENLEYSIDE

DAM

BRILLIANT DAM

SEVENMILE

DAM

WANETA

DAM

BOUNDARY DAM

LONG

LAKE

DAM

GRAND

COULEE

DAM

Wellpinit

Nespelem

SPOKANE

Colville Indian Reservation

Spokane Indian

Reservation

SLAG

REF02 REF01

SD18

SD17

SD16

SD15

SD14

SD12

SD11

SD10

T06

T05

T04

SD09

SD07

REF04

REF05

SD08

SD06 SD05

T03

T02

T01

SD04

SD03

SD02

SD01

SD13

REF03

EXPLANATION

SAMPLE SITE AND NO.

SD01 Spatially Distributed Sampling Area

T06 Target Sampling Area

REF05 Reference Site

SLAG Riverine-Slag Site

Figure 1. Location of the study area and sediment collection sites on Lake Roosevelt and the upper Columbia River, Washington and British

Columbia, April-May 2001.
Data Collection and Analysis 5

At full pool (1,290 ft), the reservoir has a surface 

area of about 80,000 acres. With the resulting lowering 

of water levels in Lake Roosevelt each year, vast 

expanses of beach and lake-bottom sediment can be 

exposed for a period of up to several months. Upon 

drying, these exposed areas provide an extremely large 

source for wind-blown dust. The maximum exposed 

area during the 2001 drawdown was estimated to be 

29,000 acres, or about 36 percent of the total surface 

area of the lake. 

Currently, the USEPA has established national 

ambient air-quality standards only for lead (1.5 g/m3) 

and PM10 (50 g/m3 annual mean, and 150 g/m3

24-hour average). The results of this study and the airmonitoring study will be used to assess the significance 

of the exposed contaminated bed sediments as a source 

of trace metals in the atmosphere above and around 

Lake Roosevelt. 

Acknowledgments

This study was completed with the assistance of 

many individuals and organizations. We thank Mark 

Munn, U.S. Geological Survey, and Patti Stone, 

Confederated Tribes of the Colville Indian Reservation, 

for their assistance in planning this investigation; Craig 

Sprankle, U.S. Bureau of Reclamation at Grand Coulee 

Dam, for providing notices of changing lake levels and 

descriptions of drawdown operations; and Ray 

DePuydt, National Park Service at Kettle Falls, for 

providing archaeological oversight in the field. Art 

Horowitz, U.S. Geological Survey Trace Element 

Laboratory in Atlanta, Ga., oversaw analysis of the 

samples and provided sampling guidance. We also 

thank Don Hurst of Fulcrum Environmental 

Consultants, Inc., and Bill Duncan of Teck Cominco 

Metals Ltd. for their technical reviews. Funding in 

support of this study was provided by the Confederated 

Tribes of the Colville Reservation, the Lake Roosevelt 

Water-Quality Council, the U.S. Bureau of 

Reclamation, the National Park Service, and the U.S. 

Geological Survey.

DATA COLLECTION AND ANALYSIS

Samples of beach and bed sediments, reference 

sample material, and riverine slag deposits were 

collected along Lake Roosevelt and the upper 

Columbia River between April 23 and May 4, 2001. 

Surficial samples of exposed beach and bed sediments 

were collected using two different, but complementary, 

sampling designs—targeted (T) and spatially 

distributed (SD). Reference samples were taken along 

the length of Lake Roosevelt and the Columbia River 

at locations above the influence of the reservoir and, on 

the river, upstream of contamination sources (fig. 1). In 

addition, a riverine slag sample was taken at about river 

mile (RM) 747 near Waneta, British Columbia, about 

8 mi downstream from Trail, British Columbia. The 

location of each of the reference and riverine-slag 

sampling sites was recorded to the nearest second of 

latitude and longitude, or within approximately the 

nearest 100 ft, using a portable Global Positioning 

System (GPS) unit at the time of collection.

Sampling Design

Six targeted sampling areas were identified 

during a pre-sampling reconnaissance survey in early 

March 2001 with members of the Lake Roosevelt 

Water-Quality Council. The sampling areas (fig. 1, 

table 1) were selected because they contained large 

expanses of exposed, fine-grained material known to 

be sources for airborne particulate matter during high 

wind events. They also were selected on the basis of 

their proximity to downwind communities and 

recreational areas. Because several of the T sites were 

extremely large, a sampling strategy was designed to 

determine the variation in the trace-element 

concentrations over the large depositional areas, and to 

determine if concentration gradients were present from 

the shoreline to the 1,290-foot contour of full-pool 

elevation.
6 Concentrations of Slag-Related Trace Elements and Mercury in Beach and Bed Sediments of Lake Roosevelt, Washington

Table 1. Location and description of sediment-sampling sites on Lake Roosevelt and the upper Columbia River, Washington and British Columbia, AprilMay 2001

[Sampling site: See figure 1 for location of sample sites. SD, spatially distributed sampling area; T, targeted area; REF, reference site. River mile: Estimated 

distance from the mouth of the Columbia River. Riverbank: Refers to the bank position as one travels downstream. Abbreviations: mi, mile]

Sample site River mile Riverbank Site description

SD01 601 Left bank Spring Canyon, south bank of Lake Roosevelt about 4 mi upstream from Grand Coulee Dam

T01 605 Right bank Swawilla Cove, about 8 mi upstream from Grand Coulee Dam on the north shore

SD02 612 Right bank North bank of Lake Roosevelt, about 3 mi downstream from the Keller Ferry

SD03 614 Left bank Keller Ferry, south bank of Lake Roosevelt

SD04 625 Right bank North bank of Lake Roosevelt, about 10 mi upstream from the Keller Ferry

REF05 635 Right bank Upper bluff area, west bank of Lake Roosevelt across from Seven Bays

T02 637 Right bank West bank of Lake Roosevelt across from Seven Bays, about 40 mi upstream from Grand 

Coulee Dam

SD05 642 Left bank East bank of Lake Roosevelt, about 3 mi upstream from the confluence of the Spokane River 

and Lake Roosevelt

SD06 644 Right bank West bank of Lake Roosevelt, about 6 mi upstream from the confluence of the Spokane 

River and Lake Roosevelt

SD07 648 Left bank East bank of Lake Roosevelt, about 9 mi upstream from the confluence of the Spokane River 

and Lake Roosevelt

T03 657 Right bank Rogers Bar, about 17 mi downstream from the Gifford Ferry on the west bank of Lake 

Roosevelt

SD08 664 Right bank West bank of Lake Roosevelt, across lake from Cedonia

REF04 670 Left bank Upper bluff at road cut on Hwy 25 about 6 mi north of Cedonia

SD09 673 Left bank Gifford Ferry, east bank of Lake Roosevelt

SD10 675 Right bank Inchelium, west bank of Lake Roosevelt

SD11 681 Left bank East bank of Lake Roosevelt, about 2 mi north of Daisy

T04 686 Right bank Barnaby Creek area, about 12 mi upstream from the Gifford Ferry on the west bank of Lake 

Roosevelt

SD12 687 Left bank East bank of Lake Roosevelt, 3 mi north of Rice

REF03 690 Right bank Upper bluff area on north side of French Rocks boat ramp

SD13 691 Right bank French Rocks area, west bank of Lake Roosevelt

SD14 691 Left bank Bradbury beach, east bank of Lake Roosevelt

SD15 699 Left bank East bank of Lake Roosevelt, south side of confluence of Colville River and Lake Roosevelt

T05 705 Left bank Marcus Flats, north of the Kettle Falls bridge on the east bank near the junction of Columbia 

River and Kettle River

T06 711 Left bank Evans, about 6 mi upstream from the Kettle Falls bridge on the east bank of Lake Roosevelt

SD16 719 Left bank North Gorge, east bank of Lake Roosevelt

SD17 724 Right bank China Bend, west bank of Lake Roosevelt

SD18 731 Right bank West bank of the Columbia River, about 4 mi downstream from Northport

Riverine slag 747 Left bank East bank of the Columbia River, about 8 mi downstream from Trail

REF02 786 Left bank North bank of Lower Arrow Lake about 8 mi upstream from Castlegar

REF01 787 Left bank North bank of Lower Arrow Lake about 10 mi upstream from Castlegar
Data Collection and Analysis 7

Selection of SD sampling areas was based 

largely on location and size of the exposed bedsediment areas. The depositional areas needed to be 

large enough that they would not be inundated if the 

reservoir water level rose slightly between the time of 

selection and the time of sampling. Eighteen SD 

depositional areas were selected between Northport 

and Grand Coulee Dam to provide a broad assessment 

of the distribution of trace elements in exposed beach 

and bed sediments (fig. 1, table 1). 

Reference samples are defined as those natural 

sediments above the influence of the Columbia River 

and the high water level of Lake Roosevelt. These 

samples were collected to assess the concentrations of 

trace elements from two areas. The first area consisted 

of beach- and bank-sediment samples from two 

locations on Lower Arrow Lake, upstream from Trail, 

British Columbia (REF01 at RM 787, and REF02 at 

RM 786, table 1; fig. 1). The second area was the 

glacial sediments above the high-water elevation along 

the upper banks of Lake Roosevelt. Three sites (REF03 

at RM 690, REF04 at RM 670, and REF05 at RM 635, 

table 1; fig. 1) were randomly selected and sampled on 

the basis of accessibility to exposed fine-grained 

material. 

A sample of a riverine-slag deposit was taken at 

RM 747, about 8 mi downstream of the smelter at Trail, 

British Columbia (fig. 1). This sample was taken from 

a depositional zone and consisted of mostly finegrained, black, sandy material, which is consistent with 

treated slag. The location of the riverine-slag sample 

was about 2 mi upstream from the site used in 1995 and 

1999 sediment surveys (Aquatic Resources Ltd., 2001; 

G3 Consulting Ltd., 2001). 

Before the sampling began, each of the T and SD 

sampling areas was identified on high-resolution (15 to 

30 m; 50 to 100 ft), near-infrared satellite images 

obtained from the LANDSAT-7 satellite. The images 

were photographed on March 6, 2001, when the 

reservoir pool elevation was low (1,224.6 ft). After 

each T and SD sampling area was identified and 

located on the LANDSAT images, the site image was 

enlarged and five approximately equally spaced 

transects were drawn across the sampling area. Three 

points were located along each transect (fig. 2), 

resulting in 15 sampling sites per area. The central 

point of each transect was located roughly midway 

between the water level and the full-pool elevation (the 

1,290-foot contour) as shown in figure 2. Full-pool 

elevation data were available in a Geographic 

Information System (GIS) coverage, which was 

combined with the LANDSAT image using imageprocessing software. The other two points were placed 

approximately 1/6 and 5/6 of the distance between the 

two water levels (fig. 2). Once the points were located 

on the LANDSAT image of the sampling areas, the 

coordinates of each point were determined using 

image-processing software. Each of the 15 sampling 

points at each of the T and SD sampling areas was 

located to within 0.5 second (25-50 ft) of the targeted 

latitude and longitude using a portable GPS unit 

programmed with the predetermined latitude and 

longitude. 

Sampling Methods 

Samples of exposed fine-grained beach and bed 

sediments were collected at 24 SD and T sampling 

areas along Lake Roosevelt (fig. 1, table 1) during the 

lowest low-water period of the 2001 drawdown (fig. 3). 

At some sampling sites, it was necessary to deviate 

several feet from the predetermined coordinates in 

order to avoid cobbles, however, the sample was 

collected to within 0.5 second of the predetermined 

latitude and longitude. If a sampling point was 

inaccessible because it was under water, an alternate 

sampling point was selected and its coordinates 

recorded using the portable GPS unit to within 

0.5 second of latitude and longitude.
8 Concentrations of Slag-Related Trace Elements and Mercury in Beach and Bed Sediments of Lake Roosevelt, Washington

500 1000 1500 METERS

0

0

1000 2000 3000 4000 5000 FEET

WATER

EXPLANATION

EXPOSED SEDIMENT

VEGETATION

SNOW COVER

SAMPLE TRANSECT

ROAD

SAMPLE SITE

FULL-POOL ELEVATION

OF LAKE ROOSEVELT

(1,290 feet above sea level)

48°

28'

30"

118°13' 118°11'30"

48°

27'

Figure 2. Example of sampling transect and spacing of sampling sites at SD12 across an exposed area of sediment on a section of Lake Roosevelt, 

Washington. 

LANDSAT image was taken on March 6, 2001. 
Data Collection and Analysis 9

Samples of the top 2 to 3 cm of exposed beach 

and bed sediments were collected using a plastic spoon 

and were placed into a plastic container where they 

were mixed to form a composite sample. At the T sites, 

three composite samples were collected from the five 

transects to determine if there was a gradient in 

concentrations from the shoreline to the 1,290-foot 

contour. This was done to assess the spatial variation in 

concentration of slag associated trace elements at the 

sampling areas. The three samples were composed of 

the following:

1. A composite of the five sampling sites nearest the 

water's edge;

2. A composite of the five sampling sites midway 

between the water and the 1,290-foot contour; and 

3. A composite of the five sampling sites nearest the 

1,290-foot contour (see fig. 2).

DAILY INSTANTANEOUS WATER LEVELS

MEASURED AT GAGING STATION 12436000

SAMPLING PERIOD, APRIL 23-MAY 4, 2001

1,200

1,210

1,220

1,230

1,240

1,250

1,260

1,270

1,280

1,290

2001

JANUARY

ELEVATION OF LAKE LEVEL, IN FEET ABOVE SEA LEVEL

FEBRUARY MARCH APRIL MAY JUNE JULY

Figure 3. Water-surface elevation of Lake Roosevelt at Grand Coulee Dam during 2001 drawdown.
10 Concentrations of Slag-Related Trace Elements and Mercury in Beach and Bed Sediments of Lake Roosevelt, Washington

At the SD sampling areas, samples from each of 

the 15 sites were composited into one sample. Mixing 

of each sample was done sequentially. That is, as new 

material was added to the container at each sampling 

site, the entire sample was thoroughly mixed. The 

resulting sample volume from each sample area was 

approximately 2 liters. The sample material then was 

removed from the container and placed in plastic bags 

for shipment to a laboratory for analysis. All equipment 

was cleaned between sites according to the following 

procedure: 

1. Wash with a dilute solution of phosphate-free 

detergent;

2. Rinse with deionized water;

3. Rinse with dilute solution of nitric acid;

4. Rinse with deionized water;

5. Allow to air dry;

6. Store in plastic bag.

All samples were shipped to the laboratory on 

ice because some of the beach and bed sediments were 

moist. 

Reference samples REF03, REF04, and REF05 

were subsurface composites. That is, an exposed bank 

above the high water line was selected, and at least the 

top 15 cm of material was removed before the sample 

was taken. Reference samples REF01 and REF02, 

collected along Lower Arrow Lake upstream from 

Trail, B.C. were surface composites and included the 

upper 2 to 3 cm of beach sediment. The reference 

samples were processed and analyzed similarly to the 

T and SD samples. The riverine-slag sample from close 

to the source was collected using the same procedures 

as used at the T and SD sites. Each of the reference and 

riverine slag samples was composed of material taken 

from only one site, not 15 as at the T and SD areas. 

Laboratory Analysis

Sediment samples were processed at the U.S. 

Geological Survey Trace Element Laboratory in Tifton, 

Ga., following methods presented in Fishman and 

Friedman (1989) and Horowitz and others (1989 and 

2001), and are not discussed in detail here. Briefly, the 

analytical methods included freeze-drying the samples, 

then sieving to obtain a size fraction of less than (<) 63 

μm. Each sample was then digested using a four-acid 

digestion process and analyzed using Inductively 

Coupled Plasma - Mass Spectrometry (ICP-MS) or 

Flame Atomic Absorption Spectroscopy (Flame-AAS) 

for trace elements (table 2). Cold Vapor-AAS was used 

to analyze for mercury (table 2). Although air-quality 

sampling commonly analyzes the size fraction less than 

10 μm (PM10), the size fraction less than 63 μm was 

used as a screening method for this investigation.

The major elements in soil—iron, manganese, 

aluminum, and titanium—and biological indicators 

total organic carbon and total carbon, sulfur, and 

nitrogen were analyzed for using combustion/gas 

analysis (table 2). Although not required for this study, 

these data are provided as a percentage of the sample 

composition to assist in the general characterization of 

each sediment sample. 

Quality Assurance

Quality-control samples were used to assess 

analytical variability, bias, and percent recovery of 

each of the trace elements analyzed for. To assess 

variability, duplicate samples were taken at selected 

sites and composed about 15 percent (n = 6) of the total 

samples submitted to the laboratory for analysis. 

Twenty percent of the samples analyzed were reagent 

blanks prepared in the laboratory that were used to 

determine if contamination was introduced during 

sample digestion and preparation. Standard reference 

material was used to assess percent recovery and the 

accuracy of the analytical method. Analytical results 

for the quality-control samples are included in 

Appendix 1.
Data Collection and Analysis 11

Table 2. Trace elements and other constituents analyzed for in fine-grained beach- and bed-sediment samples from Lake Roosevelt and 

the upper Columbia River, Washington and British Columbia, April-May 2001

[For total concentrations; wt, weight; %, percentage of sample weight; ppm, part per million; ICP-MS, Inductively Coupled Plasma-Mass 

Spectrometry; AAS, Atomic Absorption Spectrometry]

Trace element or 

constituent

Reporting 

limit Unit Method Reference

Aluminum 0.1 % ICP-MS Fishman and Friedman, 1989

Antimony .1 ppm Hydride Generation AAS Fishman and Friedman, 1989

Arsenic .1 ppm Hydride Generation AAS Fishman and Friedman, 1989

Barium 1.0 ppm ICP-MS Fishman and Friedman, 1989

Beryllium .1 ppm ICP-MS Fishman and Friedman, 1989

Cadmium .1 ppm Flame AAS Fishman and Friedman, 1989

Carbon (organic) .1 % Combustion/Gas Analysis Horowitz and others, 1989, 2001

Carbon (total) .1 % Combustion/Gas Analysis Horowitz and others, 1989, 2001

Chromium 1.0 ppm ICP-MS Fishman and Friedman, 1989

Cobalt 1.0 ppm ICP-MS Fishman and Friedman, 1989

Copper 1.0 ppm ICP-MS Fishman and Friedman, 1989

Iron .1 % ICP-MS Fishman and Friedman, 1989

Lead 1.0 ppm Flame AAS Fishman and Friedman, 1989

Lithium 1.0 ppm ICP-MS Fishman and Friedman, 1989

Manganese 1.0 ppm ICP-MS Fishman and Friedman, 1989

Mercury .01 ppm Cold Vapor AAS Fishman and Friedman, 1989

Molybdenum 5.0 ppm ICP-MS Fishman and Friedman, 1989

Nickel 1.0 ppm ICP-MS Fishman and Friedman, 1989

Nitrogen (total) .1 % Combustion/Gas Analysis Horowitz and others, 1989, 2001

Phosphorous 10.0 ppm ICP-MS Fishman and Friedman, 1989

Selenium .1 ppm Hydride Generation AAS Fishman and Friedman, 1989

Silver .5 ppm Flame AAS Fishman and Friedman, 1989

Strontium 1.0 ppm ICP-MS Fishman and Friedman, 1989

Sulfur (total) 0.1 % Combustion/Gas Analysis Horowitz and others, 1989, 2001

Tin 1.0 ppm ICP-MS Fishman and Friedman, 1989

Titanium .01 % ICP-MS Fishman and Friedman, 1989

Vanadium 1.0 ppm ICP-MS Fishman and Friedman, 1989

Zinc 1.0 ppm ICP-MS Fishman and Friedman, 1989
12 Concentrations of Slag-Related Trace Elements and Mercury in Beach and Bed Sediments of Lake Roosevelt, Washington

CONCENTRATIONS AND DISTRIBUTION 

OF SLAG-RELATED TRACE ELEMENTS AND 

MERCURY

Concentrations of 22 trace elements were 

determined for all samples along Lake Roosevelt and 

the upper Columbia River. Concentrations at the SD 

areas were used to determine the distribution of trace 

elements along Lake Roosevelt from the Canadian 

border to Grand Coulee Dam, and concentrations from 

the T areas were used to determine the distributions 

from the water line to the shore or bank. 

Concentrations of slag-related trace elements measured 

in this study were compared with those from previous 

studies and with Canadian guidelines for sediment 

quality.

Reference Sites

Sediment samples taken at the reference sites 

contained measurable concentrations of the five trace 

elements associated with slag — arsenic, cadmium, 

copper, lead, and zinc — and mercury, but at much 

lower concentrations than samples from the T, SD, and 

riverine-slag sites. Generally, the concentrations were 

one or more orders of magnitude lower (table 3). The 

concentrations of these six trace elements at the 

reference sites also were fairly uniform throughout the 

Lake Roosevelt and upper Columbia River study area 

(fig. 4). Concentrations of arsenic varied the most 

(mean = 6.48 parts per million, standard deviation = 

2.8), but were equal to or less than the measured 

concentrations at the T and SD areas (fig. 4A). 

Two of the reference sites, located at Lower 

Arrow Lake in British Columbia, were at nearly the 

same location as that reported in Bortleson and others 

(2001). The concentrations of the six trace elements at 

the two reference sites upstream from the smelter were 

nearly equivalent to those reported in the 1992 study.

Riverine-Slag Site

The trace-element concentrations of the riverineslag deposit are shown in table 3. This site was very 

near to the site used by two earlier studies (RM 746) 

that measured the bed-sediment concentrations of 

arsenic, cadmium, copper, lead, zinc, and mercury in 

1995 and in 1999 (Aquatic Resources Ltd., 2001; G3 

Consulting Ltd., 2001). A significant reduction in the 

concentrations of most of the six trace elements was 

observed between 1995 and 1999 (table 4). The 

analytical results for the sample taken at a riverine slag 

deposit in this study (2001) showed that while 

measured concentrations of arsenic, copper, and zinc 

generally were equivalent to the 1999 levels, the 

cadmium, lead, and mercury concentrations were 

higher than even the 1995 levels (table 4). These 

differences in concentrations may be attributed to 

differences in sampling locations, sampling methods, 

particle-size fraction analyzed (whole in 1995 and 

1999 and the fraction <63 μm in 2001), weathering and 

other dissipation processes, and analytical variability. 

Although mercury concentrations associated with the 

treated slag discharged from the smelter were reported 

to be less than 0.05 ppm in 1995 and 0.02 ppm in 1999 

(Aquatic Resources Ltd., 2001; G3 Consulting, Ltd., 

2001), its concentration in the 2001 riverine-slag 

deposit sample was 0.27 ppm. The mean (0.63 ppm) 

and median (0.41 ppm) mercury concentrations at the 

18 SD sampling areas were higher than in the riverineslag sample, indicating that the mercury concentrations 

vary along Lake Roosevelt and that the smelter slag 

may not be the primary source.

Targeted Areas

The T sampling areas were selected for the very 

large expanses of exposed, fine-grained bed sediments 

that are thought to be a source of dust and associated 

trace metals in the air. One objective of the sampling 

scheme was to determine the uniformity of the traceelement distribution over these large depositional 

areas. This was done by analyzing near-water, midarea, and near-bank composite samples separately to 

determine whether trace-element concentrations 

displayed gradients between the water line and the 

shore. Concentrations of several of the trace elements 

associated with slag displayed gradients between the 

water and the bank at various sampling sites. At the 

sampling areas T01, T02, and T03 in the lower part of 

the reservoir (fig. 1), concentrations of cadmium, 

copper, lead, and zinc all decreased from the water to 

the bank/shore (table 3). At T04 (RM 686), the 

concentration gradients for lead, zinc, and mercury 

were reversed, increasing from the water to the bank. 

At T05 and T06, gradient trends were not apparent for 

any of the trace elements analyzed for.
Concentrations and Distribution of Slag-Related Trace Elements and Mercury 13

Table 3. Concentrations of trace elements and other constituents analyzed for in sediment samples collected from Lake Roosevelt and the upper 

Columbia River, Washington and British Columbia, April-May 2001

[Results in microgram per gram, part per million; composition; Dup, duplicate sample; <, less than]

Sediment 

samples

Silver Copper Lead Zinc Cadmium Chromium Cobalt Nickel Barium Vanadium Lithium Beryllium Molybdenum

Phosphorous

(part per million)

Riverine slag 5.1 940 500 6,200 4.6 120 33 32 1,200 79 20 1.9 3 1,200

REF01 <.5 25 47 130 .4 130 14 65 1,100 86 30 2.5 <1 1,600

REF02 <.5 9 25 72 .3 110 9 34 820 96 18 2.1 <1 1,700

REF03 <.5 21 18 58 .2 63 10 24 1,100 85 21 1.8 <1 1,300

REF04 <.5 21 15 57 <.1 80 11 31 870 92 21 1.7 <1 1,200

REF05 <.5 25 14 53 <.1 36 8 16 790 63 29 1.7 1 760

SD01 <.5 18 23 120 .4 76 11 22 710 110 26 1.9 <1 1,300

SD01 Dup <.5 18 20 120 .4 73 11 22 760 110 26 1.9 <1 1,300

SD02 <.5 35 110 420 2.4 67 12 27 780 100 35 2.0 <1 1,000

SD03 <.5 21 24 120 .3 76 11 23 730 110 29 2.0 <1 1,100

SD04 <.5 27 57 270 1.4 81 12 27 790 120 32 2.1 <1 1,100

SD05 <.5 31 98 350 2.2 71 12 29 840 95 31 2.0 <1 1,000

SD06 <.5 30 72 240 1.6 76 12 32 900 99 33 2.1 <1 970

SD07 <.5 29 65 240 1.6 75 12 32 850 93 27 1.8 <1 1,000

SD07 Dup <.5 32 63 260 1.4 84 14 37 990 100 26 2.0 1 1,100

SD08 .7 47 180 450 3.5 86 13 35 1,000 105 29 2.1 1 1,300

SD09 <.5 32 130 330 2.2 76 12 33 1,000 93 26 2.0 1 1,100

SD10 <.5 24 41 120 .5 73 10 31 1,100 93 24 2.1 <1 1,300

SD11 .9 74 350 840 6.0 87 14 38 1,200 100 36 2.2 2 1,500

SD12 1.5 89 320 820 5.9 80 13 34 1,200 99 33 2.0 2 1,500

SD12 Dup 1.7 89 320 800 5.6 83 13 34 1,300 98 32 2.0 3 1,500

SD13 1.1 65 240 640 4.6 81 11 31 1,200 98 29 2.0 2 1,400

SD13 Dup .9 69 250 640 6.6 83 12 31 1,300 98 29 2.1 2 1,400

SD14 1.0 91 210 650 4.7 82 13 34 1,300 99 33 2.1 2 1,500

SD14 Dup 1.0 84 210 650 4.3 80 12 33 1,200 99 32 2.1 2 1,400

SD15 .6 60 240 590 3.8 75 11 28 1,200 95 26 2.0 2 1,400

SD16 1.8 125 220 1,200 5.4 80 11 28 1,250 92 23 1.8 2 1,500

SD16 Dup 2.0 130 280 1,200 5.3 80 11 28 1,700 91 22 1.8 2 1,500

SD17 2.3 150 210 1,400 4.4 81 11 28 1,200 91 22 1.9 2 1,500

SD18 2.8 200 250 1,900 5.6 82 12 28 820 88 21 1.9 2 1,500

T01-1 <.5 28 60 300 1.8 79 12 26 800 110 29 2.0 <1 1,300

T01-2 <.5 19 34 190 1.0 70 9 21 820 100 24 1.9 <1 1,200

T01-3 <.5 19 27 170 .6 83 11 24 780 120 25 2.0 <1 1,500

T02-1 <.5 22 44 210 .7 78 11 28 890 110 25 2.0 <1 1,200

T02-2 <.5 18 26 150 .6 72 10 23 840 100 25 1.9 <1 1,200

T02-3 <.5 16 20 130 .3 100 11 25 850 130 21 2.0 <1 1,500

T03-1 <.5 54 170 435 3.4 94 15 42 1,200 110 34 2.3 2 1,300

T03-2 <.5 41 160 390 2.4 100 15 40 1,200 120 28 2.3 1 1,400

T03-3 <.5 21 29 120 .3 87 12 31 1,000 110 24 2.1 <1 1,200

T04-1 <.5 31 74 260 1.5 79 11 29 960 110 30 2.0 1 1,400

T04-2 <.5 38 140 450 4.1 67 11 30 1,000 93 29 2.1 <1 1,400

T04-3 <.5 34 160 580 4.1 73 11 31 1,000 93 29 2.2 1 1,300

T05-1 1.4 110 200 790 4.3 75 13 32 1,400 89 29 2.0 3 1,500

T05-2 1.6 110 300 790 6.1 90 14 38 1,300 100 33 2.2 2 1,600

T05-3 .9 66 160 480 3.5 86 13 36 1,300 99 30 2.2 2 1,500

T06-1 1.5 120 150 970 4.5 74 11 30 1,300 87 25 1.9 3 1,500

T06-2 2.7 140 310 990 7.0 82 12 32 1,400 89 30 2.1 2 1,450

T06-3 2.4 110 300 910 6.5 81 11 31 1,400 89 28 2.0 2 1,500
14 Concentrations of Slag-Related Trace Elements and Mercury in Beach and Bed Sediments of Lake Roosevelt, Washington

Bed- and 

beachsediment 

samples

Strontium

(ppm)

Arsenic 

(ppm)

Antimony 

(ppm)

Selenium

(ppm)

Tin

(ppm)

Mercury

(ppm)

Iron

(%)

Manganese

(ppm)

Aluminum

(%)

Titanium

(%)

Total 

organic 

carbon

(%)

Total 

carbon

(%)

Total 

sulfur

(%)

Total 

nitrogen

(%)

Riverine slag 450 26 140 1.2 72 0.27 9.0 1,500 5.5 0.29 2.3 2.6 0.4 0.2

REF01 520 8.4 1.4 .3 2 .07 3.3 1,000 7.0 .42 2.2 2.2 <.1 .2

REF02 530 3.2 .6 .1 2 .02 3.4 800 6.5 .55 .6 .6 <.1 <.1

REF03 550 6.6 .6 .2 <1 .02 3.1 720 7.3 .35 <.1 .6 <.1 <.1

REF04 380 10 1.0 .1 <1 .02 3.2 540 6.2 .41 <.1 .6 <.1 <.1

REF05 370 4.2 .4 .1 1 .01 2.8 630 7.6 .37 .1 .1 <.1 <.1

SD01 320 11 1.0 .1 2 .04 4.0 760 6.4 .55 .4 .6 <.1 <.1

SD01 Dup 340 12 1.0 .2 2 <.01 3.9 670 6.4 .53 .4 .5 <.1 <.1

SD02 310 8.9 1.2 .3 3 .16 3.8 1,000 7.5 .49 1.3 1.4 <.1 .2

SD03 330 8.2 .9 .1 2 .02 4.1 820 7.0 .55 .6 .6 <.1 <.1

SD04 320 7.7 .9 .2 3 .08 4.3 1,100 7.0 .54 1.0 1.1 <.1 .1

SD05 290 10 1.3 .3 2 .17 3.5 800 7.1 .47 .9 1.0 <.1 .1

SD06 310 8.9 1.0 .2 2 .09 3.7 980 7.5 .48 .8 .9 <.1 .1

SD07 300 8.7 1.1 .3 2 .10 3.4 1,000 6.5 .48 1.0 1.0 <.1 .1

SD07 Dup 350 13 1.6 .4 4 .04 3.5 1,000 6.8 .53 1.0 1.0 <.1 .1

SD08 370 11 2.7 .5 3 .36 3.7 1,750 7.2 .44 1.0 1.1 <.1 .1

SD09 410 8.1 1.7 .3 2 .20 3.3 1,000 7.3 .42 .9 .9 <.1 .1

SD10 460 6.8 1.1 .2 1 .05 3.2 820 7.3 .39 .3 .6 <.1 <.1

SD11 360 15 5.7 .9 6 .80 4.0 1,900 7.2 .35 1.5 1.9 .1 .2

SD12 370 14 6.4 .9 6 .79 3.9 1,500 6.7 .34 1.9 2.5 .1 .2

DS12 Dup 370 15 6.7 1.0 6 .72 3.9 1,300 6.6 .34 1.9 2.5 .1 .2

SD13 390 11 4.7 .7 5 .60 3.7 1,100 6.8 .36 1.6 2.0 .1 .2

SD13 Dup 410 13 4.8 .7 5 .64 3.8 1,100 6.7 .36 1.6 2.1 .1 .2

SD14 380 12 5.7 .9 6 .46 4.0 1,200 6.7 .37 2.0 2.5 .1 .2

SD14 Dup 380 17 6.0 1.0 6 .44 4.0 1,200 6.8 .35 2.1 2.6 .1 .2

SD15 410 9.2 4.3 .6 5 .53 3.5 860 6.6 .36 1.4 2.1 .1 .2

SD16 390 12 13 1.0 11 .58 4.0 700 5.7 .33 1.4 2.8 .4 .2

SD16 Dup 390 12 12 .9 11 .55 4.0 690 5.6 .33 1.5 2.8 .3 .2

SD17 420 12 15 .9 16 1.1 4.3 890 6.0 .35 1.6 2.3 .3 .2

SD18 400 15 23 1.1 22 .41 4.8 980 5.8 .33 1.7 2.5 .5 .2

T01-1 330 11 1.4 .4 2 .07 4.2 1,000 6.7 .52 1.3 1.3 <.1 .1

T01-2 390 8.9 1.0 .2 2 .03 3.6 570 6.8 .50 .7 .8 <.1 .1

T01-3 380 10 1.0 .2 3 .01 4.4 890 6.6 .57 .7 .8 <.1 .1

T02-1 390 10 1.1 .2 2 .03 3.7 850 7.0 .51 .7 .7 <.1 <.1

T02-2 400 8.6 .8 .1 2 <.01 3.6 600 7.0 .50 .5 .5 <.1 <.1

T02-3 430 11 .8 .1 2 <.01 4.7 780 6.7 .60 .3 .4 <.1 <.1

T03-1 380 14 3.2 .7 4 .38 4.0 1,500 7.5 .43 .9 .9 <.1 .1

T03-2 440 9.4 2.6 .5 3 .25 4.0 1,200 7.4 .50 .8 .9 <.1 .1

T03-3 430 10 .9 .2 2 .01 3.7 790 6.7 .51 .4 .5 <.1 <.1

T04-1 410 11 1.4 .3 2 .06 3.9 870 7.1 .45 1.4 1.5 <.1 .2

T04-2 450 8.9 1.8 .5 3 .18 3.3 650 7.5 .44 2.2 2.2 <.1 .2

T04-3 460 6.6 1.7 .4 2 .26 3.2 610 7.2 .44 2.0 2.0 <.1 .2

T05-1 380 14 8.7 1.0 7 .26 3.9 960 6.4 .32 2.4 3.0 .3 .3

T05-2 380 19 9.5 1.0 7 .67 4.1 1,700 6.9 .35 1.8 2.2 .1 .3

T05-3 440 15 5.1 .7 4 .35 3.7 1,500 7.2 .37 1.3 1.5 .1 .2

T06-1 400 13 10 .9 7 .34 3.8 660 6.1 .32 1.9 2.8 .4 .2

T06-2 365 14 12 1.2 8 .66 3.7 610 6.3 .32 2.4 3.0 .1 .3

T06-3 380 13 9.0 1.0 7 .79 3.5 630 5.9 .32 2.2 3.0 .1 .2

Table 3. Concentrations of trace elements and other constituents analyzed for in sediment samples collected from Lake Roosevelt and the upper 

Columbia River, Washington and British Columbia, April-May 2001

[Results in microgram per gram, part per million; composition; Dup, duplicate sample; <, less than]
Concentrations and Distribution of Slag-Related Trace Elements and Mercury 15 US-CANADA

Grand Coulee Dam Grand Coulee Dam

Interim sediment quality guideline = 5.9 ppm

Interim sediment quality guideline = 0.6 ppm

Probable effect level = 17.0 ppm

Probable effect level = 3.5 ppm

BOUNDARY US-CANADA BOUNDARY

A. ARSENIC

600 625 650 675 700 725 750 775 800

RIVER MILE

0

5

10

15

20

25

30

ARSENIC CONCENTRATION, IN PARTS PER MILLION

B. CADMIUM

600 625 650 675 700 725 750 775 800

RIVER MILE

0

1

2

3

4

5

6

7

CADMIUM CONCENTRATION, IN PARTS PER MILLION

SD01 SD01

T01

T01

SD02 SD02

SD03 SD03

SD04 SD04

T02 T02

SD05 SD05 SD06 SD06

SD07 SD07

SD10 SD10

T03 T03

SD08 SD08

REF04

REF05

SD09 SD09

SD11 SD11

SD12 SD12 T04 T04

REF03 REF03 SD13 SD13 SD14 SD14

SD15 SD15

T05 T05

T06 T06

SD16 SD16

SD17 SD17SD18 SD18

REF01 REF01 REF02 REF02

SLAG SLAG

SPATIALLY DISTRIBUTED SAMPLING AREA

REFERENCE SITE

MEAN FOR TARGET SAMPLING AREA

RIVERINE-SLAG SITE

GRADIENT FOR REFERENCE SITES

GRADIENT FOR SPATIALLY DISTRIBUTED SAMPLING AREA

Figure 4. Gradients in concentrations of slag-related trace elements and mercury in fine-grained sediments along Lake Roosevelt and 

the upper Columbia River, Washington and British Columbia, April-May 2001. 
16 Concentrations of Slag-Related Trace Elements and Mercury in Beach and Bed Sediments of Lake Roosevelt, Washington

600 625 650 675 700 725 750 775 800

RIVER MILE

0

50

100

150

200

250

COPPER CONCENTRATION, IN PARTS PER MILLION

0

200

400

600

800

1,000

100

300

500

700

900

RIVERINE-SLAG CONCENTRATION, IN PARTS PER MILLION

600 625 650 675 700 725 750 775 800

RIVER MILE

0

100

200

300

400

LEAD CONCENTRATION, IN PARTS PER MILLION

0

200

400

600

100

300

500

RIVERINE-SLAG CONCENTRATION, IN PARTS PER MILLION

REF02

REF01 REF01

REF02

SD01 SD01

T01 T01

SD02 SD02

SD03 SD03

SD04 SD04

T02 T02

SD05 SD05 SD06 SD06

SD07 SD07

T03 T03

SD08 SD08

REF04 REF04

REF05 REF05

SD09 SD09

SD11 SD11

SD12 SD12 T04 T04

REF03 REF03 SD13 SD13 SD14 SD14

SD15 SD15

T05 T05

T06 T06

SD16 SD16

SD17 SD17

SD18 SD18

SD10

US-CANADA BOUNDARY

Grand Coulee Dam

SD10

US-CANADA BOUNDARY

Grand Coulee Dam

Probable effect level = 91.3 ppm

Interim sediment quality guideline = 35 ppm

Probable effect level = 197 ppm

Interim sediment quality guideline = 35.7 ppm SLAG SLAG

C. COPPER

D. LEAD

SPATIALLY DISTRIBUTED SAMPLING AREA

REFERENCE SITE

MEAN FOR TARGET SAMPLING AREA

RIVERINE-SLAG SITE

GRADIENT FOR REFERENCE SITES

GRADIENT FOR SPATIALLY DISTRIBUTED SAMPLING AREA

Figure 4.—Continued.
Concentrations and Distribution of Slag-Related Trace Elements and Mercury 17

SD10

US-CANADA BOUNDARY

Grand Coulee Dam

SD10

US-CANADA BOUNDARY

Grand Coulee Dam

Probable effect level = 0.486 ppm

Probable effect level = 315 ppm

Interim sediment quality guideline = 123 ppm

Interim sediment quality guideline = 0.17 ppm

600 625 650 675 700 725 750 775 800

RIVER MILE

0

500

1,000

1,500

2,000

ZINC CONCENTRATION, IN PARTS PER MILLION

0

2,000

4,000

7,000

1,000

3,000

5,000

6,000

RIVERINE-SLAG CONCENTRATION, IN PARTS PER MILLION

0.2

0.4

0.6

0.8

1.0

MERCURY CONCENTRATION, IN PARTS PER MILLION

600 625 650 675 700 725 750 775 800

RIVER MILE

1.2

F. MERCURY

E. ZINC

SPATIALLY DISTRIBUTED SAMPLING AREA

REFERENCE SITE

MEAN FOR TARGET SAMPLING AREA

RIVERINE-SLAG SITE

GRADIENT FOR REFERENCE SITES

GRADIENT FOR SPATIALLY DISTRIBUTED SAMPLING AREA

REF01

REF02

REF01

REF02

SD01 SD01

T01 T01

SD02 SD02

SD03 SD03

SD04 SD04

T02 T02

SD05 SD05

SD06 SD06 SD07 SD07

T03 T03

SD08 SD08

REF04 REF04

REF05 REF05

SD09 SD09

SD11 SD11

SD12 SD12 T04 T04

REF03 REF03 SD13 SD13 SD14

SD15 SD15

SD14

T05 T05

T06 T06

SD16 SD16

SD17 SD17

SD18

SD18

SLAG SLAG

0

Figure 4.—Continued.
18 Concentrations of Slag-Related Trace Elements and Mercury in Beach and Bed Sediments of Lake Roosevelt, Washington

Variations in concentration gradients from the 

water to the bank may be attributable to the size of the 

T areas. The length of the T sampling areas ranged 

from about 1.5 to about 4 mi, and the width ranged 

from about 0.3 to 2 mi. At T01, T02, and T03, the 

widths were fairly uniform, between 0.3 and 0.5 mi, 

and the 15 sampling sites were nearly evenly spaced. In 

contrast, T04, T05, and T06 were all about 2 mi long, 

but their widths ranged from 0.3 to 2 mi. The distances 

between sampling sites along a transect varied 

considerably, some being very close together (within 

300 ft) and others being separated by almost two-thirds 

of a mile. 

The disparity in the distances of the sampling 

sites from the water's edge may have contributed to the 

variation in concentration gradients. The distance 

between each of the three sampling sites on a transect 

from T01, T02, T03, and T06 were much less that those 

of T04 and T05. The occurrence of and variation in 

gradients also may be attributable to how rapidly the 

water receded from the sampling areas.

Combining the results from the three composite 

samples from each of the T sites and calculating a 

mean concentration for arsenic, cadmium, copper, lead, 

zinc, and mercury for each T sampling area resulted in 

a concentration value that was comparable to the 

nearby SD sites. Mean concentrations of cadmium, 

copper, lead, zinc, and mercury for the T sampling 

areas showed a decreasing gradient downstream from 

the International Border to the dam (figs. 4A-4F). 

Arsenic concentrations varied greatly (fig. 4A) and did 

not show any discernible trend. 

Spatially Distributed Areas

Concentrations of slag-related trace elements 

and mercury at the SD sampling areas all showed 

decreasing gradients from the Canadian border to the 

Grand Coulee Dam (fig. 4). For the slag-related trace 

elements, the magnitude and trends were similar to 

those observed in the means of concentrations at the 

T sampling areas. All these gradients, with the 

exception of arsenic, were very pronounced. 

The mean trace-element concentrations in 

surficial bed sediments at the SD sampling areas varied 

throughout the length of the reservoir, but the trends 

mostly showed high concentrations in the upper 

reaches of the reservoir that quickly decreased, highly 

variable concentrations between SD09 and SD14, and 

gradually decreasing concentrations at the lower 

reaches. The gradients are most obvious for copper and 

zinc (figs. 4C and 4E) because the magnitudes of the 

values are much larger than the variability along the 

obvious predominant trend line. Values of the square of 

the coefficient of linear correlation (r2) for plots of the 

natural logarithm of copper and zinc concentration to 

river mile are 0.796 and 0.672, respectively. 

Concentration gradients for cadmium and lead (figs. 4B

and 4D) vary greatly throughout the reservoir but 

appear to be more linear in nature. In fact, regression 

analysis for both the natural logarithm and the normal 

data resulted in similar r2 values, ranging between 

0.5 and 0.6, for both of these elements. Mercury 

appears to show a similar gradient trend (fig. 4F), but 

with even more variation.

Table 4. Comparison of slag-related trace elements and mercury 

concentrations in samples from riverine slag deposit collected April-May 

2001 with concentrations from studies in 1995 and 1999 and from treated 

slag sampled in 1992, Lake Roosevelt and the upper Columbia River, 

Washington and British Columbia

[Concentration: 1995 and 1999: Data from Aquatic Resources, Ltd. 

(2001). Sample taken at Waneta, 10 miles downstream from Cominco, Trail 

plant (about river mile 746). Concentration: 2001: 2001 riverine slag 

deposit taken at river mile 747. Treated slag: Data reported in Bortleson 

and others, 2001. <, less than; μm, micrometer]

Trace 

element

Concentration, in parts per million

(size fraction)

1995

(whole)

1999

(whole)

2001

(<63 μm)

Treated slag

(whole)

Arsenic 42 24 26 100

Cadmium 4.1 1.1 4.6 10

Copper 3,743 1,112 940 6,000

Lead 312 235 500 870

Zinc 21,433 5,727 6,200 25,000

Mercury <0.05 <0.02 0.27 <0.005
Concentrations and Distribution of Slag-Related Trace Elements and Mercury 19

The trends in concentration along the length of 

Lake Roosevelt at the T and SD sampling areas 

generally were similar to those of the 1992 study 

(Bortleson and others, 2001), when Lake Roosevelt 

bed sediments were sampled at 72 sites between the 

Northport reach of the Columbia River and Grand 

Coulee Dam, and on its major and minor tributaries and 

beaches. The trends in median concentrations for 

arsenic, cadmium, copper, lead, zinc, and mercury at 

the T and SD sites in the upper reach (T05 and T06), 

the mid-reach (T03 and T04), and the lower reach (T01 

and T02) were similar to those reported by Bortleson 

and others (2001), but the concentrations were 

significantly lower in most cases, especially for copper, 

lead, and zinc (table 5). 

Table 5. Comparison of median concentrations of slag-related trace elements and mercury with median concentrations from a 1992 study 

and with riverine slag, treated slag, and Canadian sediment-quality guidelines

[Concentrations are given in parts per million. T, targeted site; SD, spatially distributed site; reach boundaries are defined as: Lower–

confluence of Spokane River (~ river mile 639) to the Grand Coulee Dam (river mile 596); Mid–Marcus Flats (~ river mile 708) to confluence 

of Spokane River (~ river mile 639); and Upper–International boundary (river mile 745) to Marcus Flats (~ river mile 708). Concentrations in 

bold type are greater than or equal to the PEL]

Arsenic Cadmium Copper Lead Zinc Mercury

Upper Reach

T Median 14 5.3 110 250 850 0.43

SD Median 12 5.4 140 235 1,300 0.57

1992 Median1 20 6.3 300 430 2,000 1.40

Mid Reach

T Median 9.7 2.9 36 150 413 0.21

SD Median 11 3.8 60 210 590 0.44

1992 Median1 15 7.0 98 380 930 1.40

Lower Reach

T Median 9.6 0.7 21 29 120 0.01

SD Median 8.9 0.4 21 24 120 0.06

1992 Median1 16 4.7 55 190 570 0.50

All Reaches

T Median 10.5 2.6 35.0 145 401 0.21

SD Median 11.5 3.6 53.3 195 520 0.41

1992 Median1 16 6.2 85 310 970 1.3

Reference sites Median 6.6 0.3 21 18 58 0.02

Riverine slag deposit – 26 4.6 940 500 6,200 0.27

Treated slag1 – 100 10 6,000 870 25,000 <0.005

Interim sedimentquality guidelines2– 5.9 0.6 35.7 35 123 0.17

Probable effect level2 – 17.0 3.5 197 91.3 315 0.486

1From Bortleson and others, 2001.

2Canadian sediment-quality guidelines from Canadian Council of Ministers of the Environment (2002). 
20 Concentrations of Slag-Related Trace Elements and Mercury in Beach and Bed Sediments of Lake Roosevelt, Washington

Many of the sampling sites in the 1992 study 

were submerged, and the samples consisted of 

compositing the top 1.3 to 2.5 cm of several grab 

samples taken at each site. A limited number of bank 

deposits also was sampled along the middle and lower 

reaches of the reservoir. In contrast, in the current 

(2001) study, only the top few centimeters of exposed 

surficial sediments were sampled at targeted and 

spatially distributed depositional zones, and at several 

randomly chosen reference sites along the length of the 

reservoir and the Columbia River north of the reservoir. 

Differences in concentrations of the slag-related trace 

elements between the two studies can be attributed to 

natural dissipation processes that occurred over the 

course of nearly a decade between the studies, 

especially because the inputs from the major source of 

the contamination were significantly reduced. 

Sampling methods, hydrologic setting of sampling 

sites, grain size selected for analysis, and analytical 

methods also may have contributed to the differences.

During the 2001 study, concentrations of the 

major slag components, and most of the other trace 

elements analyzed for, deviated substantially from the 

trend between SD14 (RM 691) and SD10 (RM 675). 

Concentrations of most trace elements in bed sediment 

generally decreased between SD18 and SD15. Between 

SD14 and SD11, the concentrations increased, in some 

cases significantly (figs. 4A-4E). Concentrations 

decreased significantly at SD10, then increased slightly 

at SD09. The subsequent downstream sites showed a 

gradual decrease in concentration following the general 

gradient trend. 

Numerous creeks, tributaries, and drainages 

enter the entire length of the reservoir, and between 

RM 690 and RM 675, they may be the source of 

additional trace elements that account for the large 

variations in concentrations from the general trend 

between SD18 and SD15. These, along with shoreline 

landslides, appear to be the major source of finegrained sediments that enter the reservoir at irregular 

intervals along its entire length. The area around SD10 

appears to have a relatively large influx of ‘fresh’ 

glacial sediments deposited by several streams. This 

site is just downstream of the mouth of Hall Creek 

(fig. 1), which is a deep, inundated canyon with nearly 

vertical walls composed of actively eroding finegrained sediments. The creeks that flow into the 

reservoir near SD10 and T04 appear to contribute lesscontaminated sediments, and thereby act to dilute the 

concentrations of slag-related trace elements. 

Tributaries were not sampled in this study, and the only 

tributary sampled in this section of the reservoir in the 

1992 study was Hall Creek (Bortleson and others, 

2001). The reported concentrations were only slightly 

higher than those measured at SD10 in the 2001 study 

(table 6).

Table 6. Concentrations of slag-related trace elements and mercury measured at two locations 

on Hall Creek, a minor tributary entering Lake Roosevelt, and at sampling area SD10 on Lake 

Roosevelt, Washington 

[Site location: Hall Creek: Data from Bortleson and others (2001)]

Site location River 

mile

Concentration, in parts per million

Arsenic Cadmium Copper Lead Zinc Mercury

Hall Creek

left bank ~676 8.0 1.2 30 50 150 0.1

mid-stream ~676 5.5 1.3 30 28 140 0.07

SD10

right bank 675 6.8 0.5 24 41 120 0.05 
Concentrations and Distribution of Slag-Related Trace Elements and Mercury 21

Location of the sampling areas with respect to 

the right or left bank does not appear to have had an 

influence on the concentration fluctuations in this area 

because the sites were distributed fairly evenly 

between the right and left bank and there was no 

observed systematic bias. Areas SD13 and SD14 were 

located at the same river mile (RM 691), but were 

taken at opposite sides of the reservoir and had nearly 

equivalent values (table 3). Concentrations in duplicate 

samples taken at SD12, SD13, and SD14 varied only 

slightly (table 3). 

The five slag-related trace elements and mercury 

also were found at the reference sites, but 

concentrations generally were much lower than those 

at the riverine-slag site and at the T and SD sites 

upstream of SD10 (fig. 4). The trace-element 

concentrations at the reference sites varied little 

throughout the study area. Arsenic concentrations 

varied the most. 

Other Trace Elements

Trace-element concentrations may give clues to the 

distribution and origin of source material of the 

naturally occurring lake sediments, as well as 

contaminants associated with those sediments. The 

distribution of the major elements prominent in rockforming minerals provides information on the source of 

the naturally occurring trace elements in the Lake 

Roosevelt system. The percentage of composition of 

major elements in soil—iron, aluminum, and 

titanium—in the T, SD, reference, and riverine-slag 

samples (table 3) is shown in figure 5. Percentages of 

iron and aluminum varied somewhat throughout the 

sampling sites, but the concentrations of all three 

elements were nearly equivalent to the reference 

concentrations throughout the reservoir.

SD10

Grand Coulee Dam

US-CANADA BOUNDARY

EXPLANATION

SPATIALLY DISTRIBUTED SAMPLING AREA

REFERENCE SITE

MEAN FOR TARGET SAMPLING AREA

RIVERINE-SLAG SITE

GRADIENT FOR REFERENCE SITES

GRADIENT FOR SPATIALLY DISTRIBUTED SAMPLING AREA

9.0

5.5

0.3

IRON

TITANIUM

ALUMINUM

600 625 650 675 700 725 750 775 800

RIVER MILE

0

2

3

1

4

5

6

7

8

9

10

PERCENTAGE OF CONCENTRATION

REF01 REF01 REF01 REF02 REF02

SD01

REF02

SD01 SD01

T01 T01 T01

SD02 SD02 SD02

SD03 SD03 SD03

SD04 SD04 SD04

T02 T02 T02

SD05 SD05 SD05

SD06 SD06 SD06

SD07 SD07 SD07

T03 T03 T03

SD08 SD08 SD08

REF04 REF04 REF04

REF05 REF05 REF05

SD09 SD09 SD09

SD11 SD11 SD11

SD12 SD12 SD12 T04

T04 T04

REF03 REF03 REF03

SD13

SD13 SD13

SD14

SD14 SD14

SD15 SD15 SD15

T05 T05 T05

T06 T06 T06

SD16 SD16 SD16

SD17 SD17 SD17

SD18 SD18 SD18

Figure 5. Gradients in concentrations of aluminum, iron, and titanium in fine-grained sediments along Lake Roosevelt and the upper Columbia 

River, Washington and British Columbia, April-May 2001.
22 Concentrations of Slag-Related Trace Elements and Mercury in Beach and Bed Sediments of Lake Roosevelt, Washington

The other trace elements analyzed for in the 

surficial bed sediments at T and SD areas (table 2) 

varied throughout the length of the reservoir. Most of 

them did show a general decrease in concentration 

from the International Border to the Grand Coulee 

Dam, with the exception of beryllium, chromium, 

cobalt, manganese, and nickel. Of these five, all but 

manganese were near the reference concentrations. 

Gradients for concentrations of vanadium and lithium 

were reversed—concentrations increased 

downstream—but also were near the reference site 

concentrations. 

It is sometimes possible to normalize data and 

reduce site-to-site variation by using a non-reactive 

trace element as an indicator. Normalization also can 

help determine the influence of a source. In the Lake 

Roosevelt system, there are two primary sources of 

trace elements in the bed sediments—natural sources 

such as bank erosion, mineralization, and tributary 

inputs, and non-natural sources including slag and 

metallurgical effluent.

Aluminum is a component of clays and is very 

stable in the environment. The mean aluminum 

concentration at the reference sites was 6.9 ppm 

(standard deviation = 0.5), and concentrations 

increased slightly down lake (fig. 5). The mean 

aluminum concentration at the SD sites was 6.7 ppm 

(standard deviation = 0.5), very similar to the reference 

sites. The corresponding aluminum concentration in 

the riverine-slag sample was less than (5.5 ppm) the 

mean concentrations at the SD and reference sites. 

Plotting the natural logarithm of the aluminumnormalized trace-element concentration from the T and 

SD sampling areas with respect to river mile produced 

linear concentration gradients for the six trace elements 

of interest from the International Border to the dam. 

The slopes of the regression lines for cadmium, copper, 

lead, and zinc were all very similar (mean of 

0.019±0.002), with r2 values of about 0.7 when the 

outlying value at SD18 was omitted from the 

regression analysis. The slope of the regression line for 

mercury was slightly higher (0.029). The slope for 

arsenic, however, was significantly different, at 0.004, 

as evident when compared with the slopes for copper 

and zinc (fig. 6). 

The decrease in the aluminum-normalized 

cadmium, copper, lead, and zinc concentrations down 

lake indicates that the measured concentrations are not 

an artifact of grain-size variations or were not already 

in the clay particles. It also shows that the variations in 

these trace metals are not explained by variations in 

aluminum. This implies that there is a source other than 

the natural environment contributing to the presence of 

cadmium, copper, lead, and zinc in the Lake Roosevelt 

bed sediments. 

Tin is a trace element that was present in the 

riverine-slag sample at 72 ppm, but only had a median 

concentration of 1.1 ppm in the reference samples. In 

addition, tin showed a concentration gradient profile 

very similar to that of copper, lead, and zinc (fig. 7). 

Therefore, tin was used as an indicator of slag, and the 

T and SD data were normalized on the tin 

concentration. 

Plots of the natural logarithm of the tinnormalized concentrations of arsenic, cadmium, 

copper, lead, and zinc with respect to river mile all 

showed a bimodal distribution. Between SD18 and 

SD11, the normalized concentrations increased. 

Arsenic, cadmium, and lead (fig. 8), showed the 

strongest correlations, with slopes in the upper part of 

the lake that ranged from -0.030 to -0.033. The slope of 

the regression lines in the same part of the lake for 

copper and zinc were -0.007 and -0.010, respectively. 

Between SD09 and SD01, the normalized 

concentrations decreased, with the exception of arsenic 

(fig. 8). The slope of the arsenic regression line 

between SD01 and SD09 was still negative (increasing 

concentrations down lake), but it was less steep. Data 

from SD10 were not included in the regression 

analyses. 

These results indicate that the treated slag is the 

most likely source for most of the cadmium, copper, 

lead, and zinc concentrations and for the variation in 

concentrations in the bed sediments in the upper part of 

the lake from RM 747 to about SD11 (RM 681). Down 

lake of SD11, the influence of the treated-slag 

contribution to the arsenic, cadmium, copper, lead, and 

zinc concentrations seems to diminish as the influx of 

uncontaminated sediments reduce concentrations of 

these elements. 

Mercury also showed a bimodal distribution with 

increasing Sn-normalized concentrations between 

SD18 and SD11, with a slope of -0.027. Mercury 

concentrations in the bed-sediment samples from SD18 

to SD08 were two to three times higher than in the 

upstream riverine-slag sample, and indicate that the 

mercury is not directly associated with the slag. 

Analytical data from earlier reports also indicate that 

mercury is not a component of treated slag (see 

table 4), however mercury has been associated with 

slurry effluent from the smelting facility in Trail, 

British Columbia (Bortleson and others, 2001; 

G3 Consulting, Ltd., 2001.
Concentrations and Distribution of Slag-Related Trace Elements and Mercury 23 SD10

Grand Coulee Dam

US-CANADA BOUNDARY

600 625 650 675 700 725 750

RIVER MILE

0

1

-1

2

3

4

5

6

NATURAL LOGARITHM OF CONCENTRATION

CONCENTRATION, NORMALIZED

ON ALUMINUM

Zinc, slope = 0.018

Copper, slope = 0.017

Arsenic, slope = 0.004

Figure 6. Natural logarithm of the aluminum-normalized concentrations of zinc, copper, and arsenic in fine-grained 

sediments with respect to river mile along Lake Roosevelt and the upper Columbia River, Washington and British 

Columbia, April-May 2001.

SD10

US-CANADA BOUNDARY

Grand Coulee Dam

600 625 650 675 700 725 750 775 800

RIVER MILE

0

5

10

15

20

25

TIN CONCENTRATION, IN PARTS PER MILLION

0

20

40

60

80

10

30

50

70

RIVERINE-SLAG CONCENTRATION, IN PARTS PER MILLION

SPATIALLY DISTRIBUTED SAMPLING AREA

REFERENCE SITE

MEAN FOR TARGET SAMPLING AREA

RIVERINE-SLAG SITE

GRADIENT FOR REFERENCE SITES

GRADIENT FOR SPATIALLY DISTRIBUTED SAMPLING AREA

SD01

T01

SD02

SD03

SD04

T02

SD05

SD06

SD07

T03

SD08

REF04

REF05

SD09

SD11

SD12 T04

REF03 SD13

SD14

SD15

T05

T06

SD16

SD17

SD18

REF01

REF02

SLAG

Figure 7. Gradient in concentration of tin in fine-grained sediments along Lake Roosevelt and the upper Columbia River, Washington 

and British Columbia, April-May 2001.
24 Concentrations of Slag-Related Trace Elements and Mercury in Beach and Bed Sediments of Lake Roosevelt, Washington

Comparison of Concentrations of Slag-Related 

Trace Elements with Sediment-Quality Guidelines 

Concentrations of slag-related trace elements at 

the T and SD sampling areas were compared with the 

sediment-quality guidelines for freshwater 

environments developed by the Water Resources 

Branch of the Ontario Ministry of Environment and 

Energy (Persaud and others, 1991; Jaagumagi, 1993) 

and updated in 2002 (Canadian Council of Ministers of 

the Environment, 2002). These sediment-quality 

guidelines provide scientific benchmarks, or reference 

points, for evaluating the potential for observing 

adverse biological effects in aquatic systems. The 

guidelines are derived from the available toxicological 

information according to the formal protocol 

established by the Canadian Council of Ministers of the 

Environment (1995). 

The guidelines are based on two assessment 

levels of toxicity, the threshold effect level (TEL) and 

the probable effect level (PEL). The TEL is defined as 

the level below which adverse biological effects are 

expected to occur rarely, i.e., fewer than 25 percent. 

The PEL is defined as the level above which adverse 

biological effects are expected to occur frequently, i.e., 

greater than 50 percent. Interim sediment-quality 

guidelines (ISQG) are used in place of TEL when there 

is insufficient toxicological information available 

(Canadian Council of Ministers of the Environment, 

2001). For the trace elements discussed in this report, 

only ISQG and PEL values have been issued.

Concentrations of cadmium, copper, lead, zinc, 

and mercury at the reference sites were all generally 

below the ISQG. Lead and zinc concentrations at 

REF01, however, were slightly above the ISQG values. 

Concentrations at most of the T and SD areas, however, 

were consistently above the ISQG values (figs. 4B, 4C, 

4D, 4E, and 4F). The mean concentrations of arsenic at 

the reference sites (6.5 ppm) was slightly above the 

ISQG (5.9 ppm), as were the concentrations at all T 

and SD sites (fig. 4A).

SD10

US-CANADA

Grand Coulee Dam

600 625 650 675 700 725 750

RIVER MILE

-1

-2

0

-3

1

2

3

4

5

NATURAL LOGARITHM OF CONCENTRATION

EXPLANATION

SD01 TO SD09 = + 0.022

SD11 TO SD18 = - 0.033

Lead

Arsenic

SD01 TO SD09 = - 0.003

SD11 TO SD18 = - 0.030

Cadmium

SD01 TO SD09 = +0.023

SD11 TO SD18 = - 0.030

CONCENTRATION, NORMALIZED ON

TIN — Number in bold is slope

Figure 8. Natural logarithm of the tin-normalized concentrations of lead, arsenic, and cadmium in fine-grained 

sediments with respect to river mile along Lake Roosevelt and the upper Columbia River, Washington and British 

Columbia, April-May 2001.
Summary 25

Copper concentrations exceeded the PEL 

guidelines (table 5) at only one site—SD18 (fig. 4C). 

Cadmium, lead, zinc, and mercury exceeded the PEL 

guidelines (table 5) at nearly all sites above SD10, and 

nearly one-half of the sampling areas below SD10 

exceeded PEL guidelines for lead and zinc (figs. 4B, 

4D, 4E, and 4F). 

Canadian toxicity guidelines are based on the 

bioavailability of trace metals to the benthic organisms. 

While treated slag, primarily an iron silicate matrix, is 

reported to be inert and therefore not bioavailable 

(William Duncan, Teck Cominco Metals Ltd., written 

commun., April 2003), several laboratory studies have 

reported toxicity and reproductive depression for 

several test species (Bortleson and others, 1992; Godin 

and Hagen, 1992; Nener, 1992) when exposed to slag 

from the Trail, B.C. smelter. The results from a field 

study of benthic invertebrate communities (Bortleson 

and others, 1992) in three erosional habitats between 

SD18 and the International Border showed relatively 

low total abundance, diversity, and number of 

individuals that compose the EPT index. In addition, 

the communities resembled those commonly 

associated with a chemical or physical disturbance. The 

EPT index refers to the number of distinct taxa within 

the insect orders Ephemeroptera, Plecoptera, and 

Trichopetera. These groups are considered pollutionsensitive taxa. 

Implications to Airborne Trace Metal 

Concentrations

The Clean Air Act, which was last amended in 

1990, requires EPA to set National Ambient Air 

Quality Standards (NAAQS) for pollutants considered 

harmful to public health and the environment 

(http://www.epa.gov/airs/criteria.html). The Clean Air 

Act established two types of national air-quality 

standards—Primary and Secondary. Primary standards 

set limits to protect public health, including the health 

of "sensitive" populations such as asthmatics, children, 

and the elderly. Secondary standards set limits to 

protect public welfare, including protection against 

decreased visibility and damage to animals, crops, 

vegetation, and buildings.

The EPA Office of Air Quality Planning and 

Standards (OAQPS) has set NAAQS for six principal 

pollutants, which are called "criteria" pollutants. These 

are carbon monoxide, nitrogen dioxide, ozone, lead, 

particulate matter with diameters of 10 and 2.5 μm or 

less (PM10 and PM2.5), and sulfur dioxide. 

The second phase of this study will sample air in 

the study area for concentrations of particulate matter 

with diameters of 10 μm or less and most of the trace 

elements listed in table 2, with the exception of 

mercury. These data will be provided to interested 

health-related organizations. The inhalation threat from 

airborne trace elements in the ambient atmosphere, slag 

related or otherwise, is largely unknown. The health 

effects and routes of exposure, such as acute and 

chronic inhalation, of reference concentrations for the 

trace elements listed as hazardous air pollutants can be 

viewed at http://www.epa.gov/ttn/atw/hapindex.html. 

On the basis of the measured concentrations and 

areal distribution of the slag-related and other trace 

elements at the T and SD sites, the air samples are 

expected to contain a similar suite of trace elements. 

Concentrations in the air are expected to increase uplake, based on the direction of the prevailing winds. 

The Washington State Department of Ecology has an 

active air-quality monitoring program throughout the 

State. This program monitors for ozone, PM10, and 

PM2.5, but does not monitor for any associated toxic 

chemical or trace elements in the Lake Roosevelt area.

SUMMARY

Concern about the potential exposure to 

contaminated sediment from inhalation of airborne 

sediment particles along Lake Roosevelt during 

reservoir drawdown periods prompted a cooperative 

study by the U.S. Geological Survey, the Confederated 

Tribes of the Colville Reservation, the Lake Roosevelt 

Water-Quality Council, the Bureau of Reclamation, 

and the National Park Service of concentrations and 

distribution of trace elements in the fine-grained 

fraction of beach and bed sediments. The principal 

contaminants of interest in this study were trace 

elements associated with slag discharge (arsenic, 

cadmium, copper, lead, and zinc) and smelting effluent 

discharge (mercury). Each year, from about January 

through April, the water level in Lake Roosevelt is 

decreased substantially, primarily for flood-control 

purposes. Given the right exposure, drying, and wind 

conditions, significant amounts of contaminated 

sediment can be entrained into the lower atmosphere 
26 Concentrations of Slag-Related Trace Elements and Mercury in Beach and Bed Sediments of Lake Roosevelt, Washington

along Lake Roosevelt. For this study, the fine-grained 

sediments were defined as those smaller than 63 

micrometers for use as a screening method. This study 

is the first of a two-part study to assess the 

contributions from trace elements in exposed bed 

sediments to elemental concentrations of airborne 

particles.

In order to determine the concentrations and 

distribution of trace elements in the fine-grained 

fraction of exposed sediments, 24 areas along Lake 

Roosevelt and the upper Columbia River were sampled 

between April 23 and May 4, 2001. Surficial samples 

of exposed beach and bed sediments were collected 

using two different sampling designs—targeted (T) and 

spatially distributed (SD). Six T sampling areas were 

selected because they contained large areas of exposed, 

fine-grained material known to be sources for airborne 

particulate matter during high wind events and their 

proximity to downwind communities and recreational 

areas. Because several of the T sites were extremely 

large, a sampling strategy was designed to determine 

the variation in the trace-element concentrations over 

the large depositional areas, and to determine if 

concentration gradients were present from the 

shoreline to the 1,290-foot contour of full-pool 

elevation. Selection of SD sampling areas was based 

largely on location and size of the exposed bedsediment areas. Eighteen SD areas were selected 

between Northport and Grand Coulee Dam to provide a 

broad assessment of the distribution of trace elements 

in exposed beach and bed sediments along Lake 

Roosevelt. These concentrations were compared with 

concentrations at reference sites above lake level and 

upstream of contamination sources, with 

concentrations in riverine slag deposits, and with 

concentrations measured in previous studies.

The results of this study show that trace elements 

associated with treated slag and metallurgical waste are 

present in the fine-grained fraction (less than 63 

micrometers) of exposed beach and bed sediments 

along the length of Lake Roosevelt. As such, it is 

possible that these trace elements will be a component 

of the wind-blown dust resulting from the drying and 

entrainment into the lower atmosphere of the sediments 

exposed annually during the drawdown of the reservoir 

for flood-control measures.

Trace-element concentrations showed a gradient 

from water to shore at some of the targeted (T) areas. 

Of the slag-related trace elements, concentrations of 

cadmium, copper, lead, and zinc decreased from the 

water line to the bank at T01, T02, and T03, at the 

lower part of the reservoir. At area T04, the gradients 

for concentrations for lead and mercury were reversed. 

Areas T05 and T06, at the upper reach of the lake, 

showed no gradient trends for any of the trace elements 

analyzed for. 

The mean concentrations of the slag-related trace 

elements at the targeted areas (the averaged 

concentration of the three composite samples) showed 

a gradient of decreasing concentration downstream, 

from the International Border to Grand Coulee Dam. 

The trace-element concentrations at the spatially 

distributed (SD) areas varied, but the slag-related trace 

elements showed generally pronounced decreases in 

concentration from near the International Border to 

Grand Coulee Dam. Concentrations of all trace 

elements analyzed for varied greatly between SD15 

(RM 699) and SD10 (RM 675). The large variations in 

this area were attributed to the addition of natural 

sediments from streams and creeks in the area draining 

into the lake, as well as from erosive slumping of bank 

deposits. The subsequent downstream areas showed a 

gradual decrease in concentration following the general 

gradient trend. 

Concentrations of all slag-related trace elements 

generally were greater than the Canadian ISQG for 

trace metals. Cadmium, lead, zinc, and mercury, 

however, exceeded the Canadian PEL guidelines for 

trace metals at most of the sampling areas upstream 

from SD10. Both lead and zinc concentrations also 

exceeded PEL values at nearly 50 percent of the 

sampling sites downstream from SD10 as well. 

Based on the measured concentrations and areal 

distribution of slag-related and other trace elements at 

the T and SD areas, it is possible that the air samples 

collected during the second phase of this study will 

contain a similar suite of trace elements. It also is 

expected that the concentrations of trace elements in 

the air will increase up lake, based on the results of the 

sediment phase of the study and the predominant wind 

direction. 
References Cited 27

REFERENCES CITED

Aquatic Resources Ltd., 2001, Sediment and water quality in 

the lower Columbia River from Birchbank to Waneta: 

A comparison of 1995 and 1999 monitoring data: 

Prepared for Cominco Ltd., Trail Operations, Sept. 

2001, ARL Report No. 345-2, 63 p. 

Bortleson, G.C., Cox, S.E., Munn, M.D., Schumaker, R.J., 

and Block, E.K., 2001, Sediment-quality assessment of 

Franklin D. Roosevelt Lake and the upstream reach of 

the Columbia River, Washington, 1992: U.S. 

Geological Survey Water-Supply Paper 2496, 130 p. 

Canadian Council of Minsters of the Environment, 1995, 

Protocol for the derivation of Canadian sedimentquality guidelines for the protection of aquatic life: 

CME EPC-98E, Prepared by Environment Canada, 

Guidelines Division, Technical Secretariat of the 

CCME Task Group on Water-Quality Guidelines, 

Ottawa. [Reprinted in Canadian environmental quality 

guidelines, Chapter 6, CCME, 1999, Winnipeg.]

Canadian Council of Ministers of the Environment, 2001, 

Canadian sediment quality guidelines for the protection 

of aquatic life: Updated 2001. In: Canadian sediment 

quality guidelines, 1999. Canadian Council of Ministers 

of the Environment, Winnipeg. 

Canadian Council of Ministers of the Environment, 2002, 

Canadian sediment quality guidelines for the protection 

of aquatic life: Summary tables, updated. In: Canadian 

environmental quality guidelines, 1999, Canadian 

Council of Ministers of the Environment, Winnipeg, 

MB., Canada. 

Cominco, Ltd., 1991, Cominco Trail operations 

environmental report: Trail, British Columbia, 

Cominco Metals, 24 p.

Fishman, M.J., and Friedman, L.C., 1989, Methods for the 

determination of inorganic substances in water and 

fluvial sediment: U.S. Geological Survey Techniques of 

Water-Resources Investigations, Book 5, Chapter A1, 

545 p. 

G3 Consulting Ltd., 2001, Cominco Ltd. Trail Operations 

Environmental performance review of the new 

KIVCET lead smelter and elimination of slag 

discharge: Assessment of Columbia River Receiving 

Water, summary, 11 p.

Godin, B. and Hagen, M., 1992, Cominco sediment 

bioassays, sediment and water chemistry: Environment 

Canada, Regional Data Report, DR 92-13, 20 p. 

Horowitz, A.J., Elrick, K.A., and Hooper, R.P., 1989, The 

prediction of aquatic sediment-associated trace element 

concentrations using selected geochemical factors: 

Hydrological Processes, v. 3, p. 347-364.

Horowitz, A.J., Elrick, K.A., and Smith, J.J., 2001, 

Estimating suspended sediment and trace element 

fluxes in large river basins: Methodological 

Considerations as Applied to the NASQAN Program: 

Hydrological Processes, v. 15, p. 1107-1132.

Jaagumagi, R., 1993, Development of the Ontario provincial 

sediment quality guidelines for arsenic, cadmium, 

chromium, copper, lead, manganese, mercury, nickel, 

and zinc: Ontario Ministry of Environment and Energy, 

Water Resources Branch, 10 p. plus appendixes. 

Jones, F.O., Embody, D.R. and Peterson, W.L., 1961, 

Landslides along the Columbia River valley, 

northeastern Washington: U.S. Geological Survey 

Professional Paper 367, 98 p. 

Lowe, T.P., May, T.W., Brumbaugh, W.G., and Kane, D.A., 

1985, National contaminant biomonitoring program—

Concentrations of seven elements in freshwater fish, 

1978-1981: Archives of Environmental Contamination 

and Toxicology, v. 14, p. 363- 388.

Nener, J., 1992, Survival and water quality results of 

bioassays on five species of aquatic organisms exposed 

to slag from Cominco’s Trail operations: Department of 

Fisheries and Oceans, Vancouver, B.C., Canada, 20 p. 

plus tables and appendixes. 

Persaud, D., Jaagumagi, R. and Hayton, A., 1991, The 

provincial sediment-quality guidelines: Ontario 

Ministry of Environment and Energy, Water Resources 

Branch, 23 p. 

U.S. Environmental Protection Agency, 2000, Upper 

Columbia River/Lake Roosevelt river mile 597 to 745 

preliminary assessment report, Washington: TDD: 99-

10-0002, U.S. Environmental Protection Agency 

Superfund Technical Assessment and Response Team, 

variously paginated.

Yake, W.E., 1979, Water quality trend analysis — the 

Spokane River basin: Washington State Department of 

Ecology, DOE-PR-6, 44 p.
28 Concentrations of Slag-Related Trace Elements and Mercury in Beach and Bed Sediments of Lake Roosevelt, Washington

Appendix 1. Analytical results and relative standard deviations for duplicate samples and National Institute of Standards Technology reference material 

for quality control

[Duplicates: REF, reference site; SD, spatially distributed area; T, targeted area and sample number; DUP, duplicate sample; RSD, relative standard deviation. 

Standard reference material: NIST, National Institute of Standards and Technology; USGS, U.S. Geological Survey. Values in parentheses are uncertified 

values and are included for reference only. ppm, parts per million in micrograms per gram; %, percent; NA, not applicable; ND, not detected; <, less than]

Duplicates

Silver Copper Lead Zinc Cadmium Mercury Chromium Cobalt Nickel Barium Vandium Lithium Beryllium

Molybdenum

(ppm)

REF02 <0.5 8.8 25 73 0.2 0.02 110 9 34 830 96 18 2.1 <1

DUP REF02 <0.5 8.5 25 71 0.3 0.01 110 9 33 820 96 18 2.1 <1

RSD NA 0.2 0 1 0.1 0.01 0 0 1 7 0 0 0 NA

SD08 0.7 46 180 460 3.4 0.37 87 13 35 1,000 110 29 2.1 1.2

DUP SD08 <0.5 47 180 440 3.5 0.35 85 13 35 1,000 100 29 2.1 1.1

RSD NA 1 0 14 0.1 0.01 1 0 0 0 7 0 0 0.1

SD16 1.9 130 220 1,200 5.3 0.61 80 11 28 1,200 92 23 1.8 2.1

DUP SD16 1.6 120 220 1,200 5.5 0.55 79 11 28 1,300 91 22 1.8 2.1

RSD 0.2 7 0 0 0.1 0.04 1 0 0 71 1 1 0 0

T0310 <0.5 54 170 420 3.3 0.36 93 14 41 1,200 110 34 2.2 1.4

DUP T0310 0.5 54 170 450 3.4 0.40 94 15 43 1,200 110 33 2.3 1.6

RSD NA 0 0 21 0.1 0.03 1 1 1 0 0 1 0.1 0.1

T0620 2.8 140 310 990 6.9 0.68 82 12 32 1,400 89 30 2.1 2.4

DUP T0620 2.6 150 310 980 7.1 0.64 81 12 31 1,400 89 30 2.0 2.3

RSD 0.1 7 0 7 0.1 0.03 1 0 1 0 0 0 0.1 0.1

Standard 

reference 

material

Silver Copper Lead Zinc Cadmium Mercury Chromium Cobalt Nickel Barium Vandium Lithium Beryllium

Molybdenum

(ppm)

NIST 2709

Reported value

<0.5 35+1 19+1 106+3 0.4+0.01 1.40+0.08 130+4 13+1 88+5 970+4

0

112+5 ND ND (2)

Found <0.5 34 18 100 0.3 1.3 120 13 85 940 110 58 5.0 2

Found <0.5 34 18 100 0.3 1.4 120 13 84 990 110 56 5.3 2

NIST 2711

Reported value

4.6+0.4 114+2 1,162+3

0

350+5 41.7+0.3 6.25+0.19 (47) (10) 21+1 730+4

0

82+3 ND ND (2)

Found 4.6 110 1,200 350 41.0 6.3 49 10 21 710 80 29 2.1 1

Found 4.5 110 1,200 350 40.0 6.1 48 10 21 760 80 28 2.1 2

NIST 1646A

Reported value

<0.5 10+0.3 12+1 49+2 0.15+0.07 0.04 41+2 5 23 210 45+1 17 <1 1.8

Found <0.5 10 11 50 0.1 0.03 43 5 26 210 46 17 0.9 2

Found <0.5 10 10 48 <0.1 0.02 44 5 25 230 45 16 0.9 2

USGS MAG-1

Reported value

0.08+0.02 30+3 24+3 130+6 0.2+.03 (0.02) 97+8 20+2 53+8 480+4

1

140+6 79+4 3.2+0.4 2+1

Found <0.5 27 27 130 0.1 0.05 110 21 52 480 140 84 2.9 1

Found <0.5 27 27 140 <0.1 0.04 110 21 52 500 140 85 2.9 1

USGS RGM-1

Reported value

<0.5 12+2 24+3 32+6 0.1 0.02 4+1 2+1 4+2 807+4

6

13+2 57+8 2.4+0.2 2+1

Found <0.5 10 25 32 0.1 0.01 5 2 2 850 12 62 2.3 2

Found <0.5 11 24 36 <0.1 <0.01 5 2 2 880 12 65 2.4 3

USGS SDO-1

Reported value

0.2 60+10 28+5 64+7 <2-<10 0.19+0.08 66+8 47+6 100+10 ND 160+20 29+6 3.3+0.6 130+20

Found <0.5 57 23 66 0.1 0.19 74 46 100 ND 160 32 3.0 140

Found <0.5 57 25 64 <0.1 0.14 79 49 100 ND 160 31 3.0 150
Appendix 1 29

Duplicates

Phosphorus

(ppm)

Strontium

(ppm)

Arsenic

(ppm)

Antimony

(ppm)

Selenium

(ppm)

Tim

(ppm)

Iron

(%)

Manganese

(ppm)

Aluminum

(%)

Titanium

(%)

Total 

organic 

carbon

(%)

Total 

carbon

(%$)

Total 

sulfur

(%)

Total 

nitrogen

(%)

REF02 1,700 530 2.9 0.5 0.1 2.4 3.4 790 6.5 0.54 0.4 0.5 <0.1 <0.1

DUP REF02 1,700 530 3.4 0.7 0.1 1.3 3.4 810 6.4 0.55 0.7 0.4 <0.1 <0.1

RSD 0 0 0.4 0.1 0 0.8 0 14 0.1 0.01 0.2 0.1 NA NA

SD08 1,300 370 11 2.6 0.4 3.6 3.7 1,700 7.2 0.44 1.0 1.1 <0.1 0.1

DUP SD08 1,300 370 11 2.8 0.5 3.2 3.7 1,800 7.1 0.43 1.0 1.1 <0.1 0.1

RSD 0 0 0 0.1 0.1 0.3 0 71 0.1 0.01 0 0 NA 0

SD16 1,500 390 11 12 1.0 11 4.0 710 5.7 0.33 1.4 2.8 0.4 0.2

DUP SD16 1,500 390 13 14 1.0 11 4.0 680 5.6 0.33 1.4 2.7 0.3 0.2

RSD 0 0 1 1.4 0 0 0 21 0.1 0 0 0.1 0.1 0

T0310 1,300 370 14 3.0 0.6 3.3 3.9 1,500 7.5 0.42 0.9 0.9 <0.1 0.1

DUP T0310 1,300 390 14 3.4 0.7 3.7 4.0 1,500 7.5 0.43 0.9 0.9 <0.1 0.2

RSD 0 14 0 0.3 0.1 0.3 0.1 0 0 0.01 0 0 NA 0

T0620 1,500 370 14 12 1.2 8.7 3.7 610 6.3 0.32 2.3 2.9 0.1 0.3

DUP T0620 1,400 360 14 12 1.2 7.5 3.7 610 6.2 0.32 2.4 3.0 0.1 0.3

RSD 71 7 0 0 0 0.8 0 0 0.1 0 0.1 0.1 0 0

Standard 

reference 

material

Phosphorus

(ppm)

Strontium

(ppm)

Arsenic

(ppm)

Antimony

(ppm)

Selenium

(ppm)

Tim

(ppm)

Iron

(%)

Manganese

(ppm)

Aluminum

(%)

Titanium

(%)

Total 

organic 

carbon

(%)

Total 

carbon

(%)

Total 

sulfur

(%)

Total 

nitrogen

(%)

NIST 2709

Reported value

620+50 230+2 18+1 7.9+.6 1.6+0.1 ND 3.5+0.1 540+20 7.5+0.1 0.34+0.02 1.2 1.2 0.1 ND

Found 620 230 19 7.7 1.8 1 3.6 550 7.6 0.33 1.0 1.1 0.1 0.1

Found 610 230 18 7.3 1.7 <1 3.5 550 7.4 0.33 1.0 1.2 0.1 0.1

NIST 2711

Reported value

860+70 245+1 105+8 19+2 1.5+0.1 ND 2.9+0.1 640+30 6.5+0.1 0.31+0.02 2.0 2.0 0 ND

Found 790 240 100 20 1.5 4 2.9 660 6.6 0.29 1.8 1.7 <0.1 0.1

Found 800 250 100 21 1.5 4 2.9 630 6.6 0.29 1.7 1.7 <0.1 0.2

NIST 1646A

Reported value

270+10 68 6.2+0.

2

0.30 0.2+0.1 1 2.0+0.1 234+3 2.3+0.02 0.46+0.02 ND ND 0.3+0.1 ND

Found 300 74 6.3 0.3 0.2 1 2.0 220 2.3 0.47 0.5 0.6 0.3 <0.1

Found 290 76 6.2 0.3 0.3 1 2.0 240 2.3 0.45 0.5 0.6 0.3 <0.1

USGS MAG-1

Reported value

700+100 146+15 9.2+1.

2

1.0+0.1 1.2+0.1 3.6+1 4.8+0.2 760+70 8.7+0.2 0.45+0.04 2.15+0.4 2.15+0.4 0.4+0.1 0.08

Found 700 140 9.8 0.9 1.4 3 4.8 740 8.7 0.42 2.2 2.2 0.2 0.3

Found 700 140 9.7 0.9 1.6 3 4.8 710 8.6 0.41 2.2 2.2 0.2 0.3

USGS RGM-1

Reported value

210+15 108+10 3.0+.4 1.3+0.1 <0.1 4.1+0.4 1.3+0.1 282+30 7.3+0.1 0.16+0.02 <0.1 <0.1 <0.1 ND

Found 190 100 2.4 1.0 <0.1 3 1.3 280 7.2 0.17 <0.1 <0.1 <0.1 <0.1

Found 190 110 2.7 1.3 <0.1 3 1.3 290 7.3 0.17 <0.1 <0.1 <0.1 <0.1

USGS SDO-1

Reported value

480+30 75+11 69+9 4.1-4.8 1.9-6.8 3.7+1.2 6.5+0.2 320+40 6.5+0.1 0.43+0.02 10+0.4 10+.4 5.4+0.4 0.35

Found 470 78 70 3.7 2.3 2 6.4 300 6.3 0.40 9.7 9.5 4.8 0.4

Found 470 82 65 5.0 1.6 3 6.4 290 6.5 0.40 9.4 9.5 4.8 0.4

Appendix 1. Analytical results and relative standard deviations for duplicate samples and National Institute of Standards Technology reference material 

for quality control—Continued

[Duplicates: REF, reference site; SD, spatially distributed area; T, targeted area and sample number; DUP, duplicate sample; RSD, relative standard deviation. 

Standard reference material: NIST, National Institute of Standards and Technology; USGS, U.S. Geological Survey. Values in parentheses are uncertified 

values and are included for reference only. ppm, parts per million in micrograms per gram; %, percent; NA, not applicable; ND, not detected; <, less than]
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